Commit Graph

8824 Commits

Author SHA1 Message Date
Josef Bacik
0024652895 btrfs: rename btrfs_put_fs_root and btrfs_grab_fs_root
We are now using these for all roots, rename them to btrfs_put_root()
and btrfs_grab_root();

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:33 +01:00
Josef Bacik
bd647ce385 btrfs: add a leak check for roots
Now that we're going to start relying on getting ref counting right for
roots, add a list to track allocated roots and print out any roots that
aren't freed up at free_fs_info time.

Hide this behind CONFIG_BTRFS_DEBUG because this will just be used for
developers to verify they aren't breaking things.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:33 +01:00
Josef Bacik
8260edba67 btrfs: make the init of static elements in fs_info separate
In adding things like eb leak checking and root leak checking there were
a lot of weird corner cases that come from the fact that

  1) We do not init the fs_info until we get to open_ctree time in the
     normal case and

  2) The test infrastructure half-init's the fs_info for things that it
     needs.

This makes it really annoying to make changes because you have to add
init in two different places, have special cases for testing fs_info's
that may not have certain things initialized, and cases for fs_info's
that didn't make it to open_ctree and thus are not fully set up.

Fix this by extracting out the non-allocating init of the fs info into
it's own public function and use that to make sure we're all getting
consistent views of an allocated fs_info.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:33 +01:00
Josef Bacik
ae18c37ad5 btrfs: move fs_info init work into it's own helper function
open_ctree mixes initialization of fs stuff and fs_info stuff, which
makes it confusing when doing things like adding the root leak
detection.  Make a separate function that inits all the static
structures inside of the fs_info needed for the fs to operate, and then
call that before we start setting up the fs_info to be mounted.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:33 +01:00
Josef Bacik
141386e1a5 btrfs: free more things in btrfs_free_fs_info
Things like the percpu_counters, the mapping_tree, and the csum hash can
all be freed at btrfs_free_fs_info time, since the helpers all check if
the structure has been initialized already.  This significantly cleans
up the error cases in open_ctree.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:32 +01:00
Josef Bacik
bc44d7c4b2 btrfs: push btrfs_grab_fs_root into btrfs_get_fs_root
Now that all callers of btrfs_get_fs_root are subsequently calling
btrfs_grab_fs_root and handling dropping the ref when they are done
appropriately, go ahead and push btrfs_grab_fs_root up into
btrfs_get_fs_root.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:32 +01:00
Josef Bacik
81f096edf0 btrfs: use btrfs_put_fs_root to free roots always
If we are going to track leaked roots we need to free them all the same
way, so don't kfree() roots directly, use btrfs_put_fs_root.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:32 +01:00
Josef Bacik
4c78e9f596 btrfs: hold a ref on the root in open_ctree
We lookup the fs_root and put it in our fs_info directly, we should hold
a ref on this root for the lifetime of the fs_info.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:32 +01:00
Josef Bacik
0d4b046301 btrfs: export and rename free_fs_info
We're going to start freeing roots and doing other complicated things in
free_fs_info, so we need to move it to disk-io.c and export it in order
to use things lik btrfs_put_fs_root().

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:32 +01:00
Josef Bacik
fbb0ce40d6 btrfs: hold a ref on the root in btrfs_check_uuid_tree_entry
We lookup the uuid of arbitrary subvolumes, hold a ref on the root while
we're doing this.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:31 +01:00
Josef Bacik
ca2037fba6 btrfs: hold a ref on the root in btrfs_recover_log_trees
We replay the log into arbitrary fs roots, hold a ref on the root while
we're doing this.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:31 +01:00
Josef Bacik
5119cfc36f btrfs: hold a ref on the root in create_pending_snapshot
We create the snapshot and then use it for a bunch of things, we need to
hold a ref on it while we're messing with it.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:31 +01:00
Josef Bacik
5168489a07 btrfs: hold a ref on the root in get_subvol_name_from_objectid
We lookup the name of a subvol which means we'll cross into different
roots.  Hold a ref while we're doing the look ups in the fs_root we're
searching.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:31 +01:00
Josef Bacik
6f9a3da5da btrfs: hold a ref on the root in btrfs_ioctl_send
We lookup all the clone roots and the parent root for send, so we need
to hold refs on all of these roots while we're processing them.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:31 +01:00
Josef Bacik
fd79d43b34 btrfs: hold a ref on the root in scrub_print_warning_inode
We look up the root for the bytenr that is failing, so we need to hold a
ref on the root for that operation.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:30 +01:00
Josef Bacik
0b2dee5cff btrfs: hold a ref for the root in btrfs_find_orphan_roots
We lookup roots for every orphan item we have, we need to hold a ref on
the root while we're doing this work.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:30 +01:00
Josef Bacik
9f583209f2 btrfs: push grab_fs_root into read_fs_root
All of relocation uses read_fs_root to lookup fs roots, so push the
btrfs_grab_fs_root() up into that helper and remove the individual
calls.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:30 +01:00
Josef Bacik
932fd26df8 btrfs: hold a ref on the root in btrfs_recover_relocation
We look up the fs root in various places in here when recovering from a
crashed relcoation.  Make sure we hold a ref on the root whenever we
look them up.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:30 +01:00
Josef Bacik
76deacf023 btrfs: hold a ref on the root in create_reloc_inode
We're creating a reloc inode in the data reloc tree, we need to hold a
ref on the root while we're doing that.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:30 +01:00
Josef Bacik
3d7babdcf2 btrfs: hold a ref on the root in find_data_references
We're looking up the data references for the bytenr in a root, we need
to hold a ref on that root while we're doing that.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:30 +01:00
Josef Bacik
442b1ac524 btrfs: hold a ref on the root in record_reloc_root_in_trans
We are recording this root in the transaction, so we need to hold a ref
on it until we do that.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:29 +01:00
Josef Bacik
ab9737bd75 btrfs: hold a ref on the root in merge_reloc_roots
We look up the corresponding root for the reloc root, we need to hold a
ref while we're messing with it.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:29 +01:00
Josef Bacik
db2c2ca2db btrfs: hold a ref on the root in prepare_to_merge
We look up the reloc roots corresponding root, we need to hold a ref on
that root.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:29 +01:00
Josef Bacik
0b530bc5e1 btrfs: hold a ref on the root in build_backref_tree
This is trickier than the previous conversions.  We have backref_node's
that need to hold onto their root for their lifetime.  Do the read of
the root and grab the ref.  If at any point we don't use the root we
discard it, however if we use it in our backref node we don't free it
until we free the backref node.  Any time we switch the root's for the
backref node we need to drop our ref on the old root and grab the ref on
the new root, and if we dupe a node we need to get a ref on the root
there as well.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:29 +01:00
Josef Bacik
2a2b5d6202 btrfs: hold ref on root in btrfs_ioctl_default_subvol
We look up an arbitrary fs root here, we need to hold a ref on the root
for the duration.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:29 +01:00
Josef Bacik
04734e8448 btrfs: hold a ref on the root in btrfs_ioctl_get_subvol_info
We look up whatever root userspace has given us, we need to hold a ref
throughout this operation. Use 'root' only for the on fs root and not as
a temporary variable elsewhere.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:28 +01:00
Josef Bacik
b8a49ae191 btrfs: hold a ref on the root in btrfs_search_path_in_tree_user
We can wander into a different root, so grab a ref on the root we look
up.  Later on we make root = fs_info->tree_root so we need this separate
out label to make sure we do the right cleanup only in the case we're
looking up a different root.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:28 +01:00
Josef Bacik
88234012be btrfs: hold a ref on the root in btrfs_search_path_in_tree
We look up an arbitrary fs root, we need to hold a ref on it while we're
doing our search.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:28 +01:00
Josef Bacik
3ca35e839e btrfs: hold a ref on the root in search_ioctl
We lookup a arbitrary fs root, we need to hold a ref on that root.  If
we're using our own inodes root then grab a ref on that as well to make
the cleanup easier.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:28 +01:00
Josef Bacik
fc92f79856 btrfs: hold a ref on the root in create_subvol
We're creating the new root here, but we should hold the ref until after
we've initialized the inode for it.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:28 +01:00
Josef Bacik
8727002f79 btrfs: hold a ref on the root in fixup_tree_root_location
Looking up the inode from an arbitrary tree means we need to hold a ref
on that root.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:28 +01:00
Josef Bacik
02162a0265 btrfs: hold a ref on the root in __btrfs_run_defrag_inode
We are looking up an arbitrary inode, we need to hold a ref on the root
while we're doing this.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:27 +01:00
Josef Bacik
bdf70b9e75 btrfs: hold a root ref in btrfs_get_dentry
Looking up the inode we need to search the root, make sure we hold a
reference on that root while we're doing the lookup.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:27 +01:00
Josef Bacik
9326f76f4b btrfs: hold a ref on the root in resolve_indirect_ref
We're looking up a random root, we need to hold a ref on it while we're
using it.

Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:27 +01:00
Josef Bacik
af01d2e53f btrfs: hold a ref on fs roots while they're in the radix tree
If the root is sitting in the radix tree, we should probably have a ref
for the radix tree.  Grab a ref on the root when we insert it, and drop
it when it gets deleted.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:27 +01:00
Josef Bacik
4b8b052888 btrfs: describe the space reservation system in general
Add another comment to cover how the space reservation system works
generally.  This covers the actual reservation flow, as well as how
flushing is handled.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:27 +01:00
Josef Bacik
6f4ad559ea btrfs: add a comment describing delalloc space reservation
delalloc space reservation is tricky because it encompasses both data
and metadata.  Make it clear what each side does, the general flow of
how space is moved throughout the lifetime of a write, and what goes
into the calculations.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:27 +01:00
Josef Bacik
734d8c15df btrfs: add a comment describing block reserves
This is a giant comment at the top of block-rsv.c describing generally
how block reserves work.  It is purely about the block reserves
themselves, and nothing to do with how the actual reservation system
works.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:26 +01:00
Josef Bacik
4cdfd93002 btrfs: handle NULL roots in btrfs_put/btrfs_grab_fs_root
We want to use this for dropping all roots, and in some error cases we
may not have a root, so handle this to make the cleanup code easier.
Make btrfs_grab_fs_root the same so we can use it in cases where the
root may not exist (like the quota root).

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:26 +01:00
Josef Bacik
a98db0f304 btrfs: make the fs root init functions static
Now that the orphan cleanup stuff doesn't use this directly we can just
make them static.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:26 +01:00
Josef Bacik
3619c94f07 btrfs: open code btrfs_read_fs_root_no_name
All this does is call btrfs_get_fs_root() with check_ref == true.  Just
use btrfs_get_fs_root() so we don't have a bunch of different helpers
that do the same thing.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:26 +01:00
Josef Bacik
83db2aadb3 btrfs: remove btrfs_read_fs_root, not used anymore
All helpers should either be using btrfs_get_fs_root() or
btrfs_read_tree_root().

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:26 +01:00
Josef Bacik
3dbf1738a1 btrfs: make relocation use btrfs_read_tree_root()
Relocation has it's special roots, we don't want to save these in the
root cache either, so swap it to use btrfs_read_tree_root().  However
the reloc root does need REF_COWS set, so make sure we set it everywhere
we use this helper, as it no longer does the REF_COWS setting.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:25 +01:00
Josef Bacik
62a2c73ebd btrfs: export and use btrfs_read_tree_root for tree-log
Tree-log uses btrfs_read_fs_root to load its log, but this just calls
btrfs_read_tree_root.  We don't save the log roots in our root cache, so
just export this helper and use it in the logging code.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:25 +01:00
Josef Bacik
e59d18b45d btrfs: make btrfs_find_orphan_roots use btrfs_get_fs_root
btrfs_find_orphan_roots has this weird thing where it looks up the root
in cache to see if it is there before just reading the root.  But the
read it uses just reads the root, it doesn't do any of the init work, we
do that by hand here.  But this is unnecessary, all we really want is to
see if the root still exists and add it to the dead roots list to be
cleaned up, otherwise we delete the orphan item.

Fix this by just using btrfs_get_fs_root directly with check_ref set to
false so we get the orphan root items.  Then we just handle in cache and
out of cache roots the same, add them to the dead roots list and carry
on.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:25 +01:00
Josef Bacik
f39e457156 btrfs: move fs root init stuff into btrfs_init_fs_root
We have a helper for reading fs roots that just reads the fs root off
the disk and then sets REF_COWS and init's the inheritable flags.  Move
this into btrfs_init_fs_root so we can later get rid of this helper and
consolidate all of the fs root reading into one helper.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:25 +01:00
Josef Bacik
96dfcb46ff btrfs: push __setup_root into btrfs_alloc_root
There's no reason to not init the root at alloc time, and with later
patches it actually causes problems if we error out mounting the fs
before the tree_root is init'ed because we expect it to have a valid ref
count.  Fix this by pushing __setup_root into btrfs_alloc_root.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:25 +01:00
Josef Bacik
3f1c64ce04 btrfs: delete the ordered isize update code
Now that we have a safe way to update the isize, remove all of this code
as it's no longer needed.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:24 +01:00
Josef Bacik
d923afe96d btrfs: replace all uses of btrfs_ordered_update_i_size
Now that we have a safe way to update the i_size, replace all uses of
btrfs_ordered_update_i_size with btrfs_inode_safe_disk_i_size_write.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:24 +01:00
Josef Bacik
9ddc959e80 btrfs: use the file extent tree infrastructure
We want to use this everywhere we modify the file extent items
permanently.  These include:

  1) Inserting new file extents for writes and prealloc extents.
  2) Truncating inode items.
  3) btrfs_cont_expand().
  4) Insert inline extents.
  5) Insert new extents from log replay.
  6) Insert a new extent for clone, as it could be past i_size.
  7) Hole punching

For hole punching in particular it might seem it's not necessary because
anybody extending would use btrfs_cont_expand, however there is a corner
that still can give us trouble.  Start with an empty file and

fallocate KEEP_SIZE 1M-2M

We now have a 0 length file, and a hole file extent from 0-1M, and a
prealloc extent from 1M-2M.  Now

punch 1M-1.5M

Because this is past i_size we have

[HOLE EXTENT][ NOTHING ][PREALLOC]
[0        1M][1M   1.5M][1.5M  2M]

with an i_size of 0.  Now if we pwrite 0-1.5M we'll increas our i_size
to 1.5M, but our disk_i_size is still 0 until the ordered extent
completes.

However if we now immediately truncate 2M on the file we'll just call
btrfs_cont_expand(inode, 1.5M, 2M), since our old i_size is 1.5M.  If we
commit the transaction here and crash we'll expose the gap.

To fix this we need to clear the file extent mapping for the range that
we punched but didn't insert a corresponding file extent for.  This will
mean the truncate will only get an disk_i_size set to 1M if we crash
before the finish ordered io happens.

I've written an xfstest to reproduce the problem and validate this fix.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:24 +01:00
Josef Bacik
41a2ee75aa btrfs: introduce per-inode file extent tree
In order to keep track of where we have file extents on disk, and thus
where it is safe to adjust the i_size to, we need to have a tree in
place to keep track of the contiguous areas we have file extents for.

Add helpers to use this tree, as it's not required for NO_HOLES file
systems.  We will use this by setting DIRTY for areas we know we have
file extent item's set, and clearing it when we remove file extent items
for truncation.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:24 +01:00
Josef Bacik
790a1d44f9 btrfs: use btrfs_ordered_update_i_size in clone_finish_inode_update
We were using btrfs_i_size_write(), which unconditionally jacks up
inode->disk_i_size.  However since clone can operate on ranges we could
have pending ordered extents for a range prior to the start of our clone
operation and thus increase disk_i_size too far and have a hole with no
file extent.

Fix this by using the btrfs_ordered_update_i_size helper which will do
the right thing in the face of pending ordered extents outside of our
clone range.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:24 +01:00
Su Yue
cfe953c824 btrfs: update the comment of btrfs_control_ioctl()
Btrfsctl was removed in 2012, now the function btrfs_control_ioctl()
is only used for devices ioctls. So update the comment.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Su Yue <Damenly_Su@gmx.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:23 +01:00
Qu Wenruo
0c89138970 btrfs: relocation: Add introduction of how relocation works
Relocation is one of the most complex part of btrfs, while it's also the
foundation stone for online resizing, profile converting.

For such a complex facility, we should at least have some introduction
to it.

This patch will add an basic introduction at pretty a high level,
explaining:

- What relocation does
- How relocation is done
  Only mentioning how data reloc tree and reloc tree are involved in the
  operation.
  No details like the backref cache, or the data reloc tree contents.
- Which function to refer.

More detailed comments will be added for reloc tree creation, data reloc
tree creation and backref cache.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:23 +01:00
Filipe Manana
42836cf4ba Btrfs: don't iterate mod seq list when putting a tree mod seq
Each new element added to the mod seq list is always appended to the list,
and each one gets a sequence number coming from a counter which gets
incremented everytime a new element is added to the list (or a new node
is added to the tree mod log rbtree). Therefore the element with the
lowest sequence number is always the first element in the list.

So just remove the list iteration at btrfs_put_tree_mod_seq() that
computes the minimum sequence number in the list and replace it with
a check for the first element's sequence number.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:23 +01:00
Qu Wenruo
30b3688e1f btrfs: Add overview of device replace
The overview of btrfs dev-replace.  It mentions some corner cases caused
by the write duplication and scrub based data copy.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ adjust wording ]
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:23 +01:00
Linus Torvalds
67d584e33e for-5.6-rc6-tag
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Merge tag 'for-5.6-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "Two fixes.

  The first is a regression: when dropping some incompat bits the
  conditions were reversed. The other is a fix for rename whiteout
  potentially leaving stack memory linked to a list"

* tag 'for-5.6-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: fix removal of raid[56|1c34} incompat flags after removing block group
  btrfs: fix log context list corruption after rename whiteout error
2020-03-22 11:35:33 -07:00
Filipe Manana
d8e6fd5c79 btrfs: fix removal of raid[56|1c34} incompat flags after removing block group
We are incorrectly dropping the raid56 and raid1c34 incompat flags when
there are still raid56 and raid1c34 block groups, not when we do not any
of those anymore. The logic just got unintentionally broken after adding
the support for the raid1c34 modes.

Fix this by clear the flags only if we do not have block groups with the
respective profiles.

Fixes: 9c907446dc ("btrfs: drop incompat bit for raid1c34 after last block group is gone")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-20 21:31:32 +01:00
Filipe Manana
236ebc20d9 btrfs: fix log context list corruption after rename whiteout error
During a rename whiteout, if btrfs_whiteout_for_rename() returns an error
we can end up returning from btrfs_rename() with the log context object
still in the root's log context list - this happens if 'sync_log' was
set to true before we called btrfs_whiteout_for_rename() and it is
dangerous because we end up with a corrupt linked list (root->log_ctxs)
as the log context object was allocated on the stack.

After btrfs_rename() returns, any task that is running btrfs_sync_log()
concurrently can end up crashing because that linked list is traversed by
btrfs_sync_log() (through btrfs_remove_all_log_ctxs()). That results in
the same issue that commit e6c617102c ("Btrfs: fix log context list
corruption after rename exchange operation") fixed.

Fixes: d4682ba03e ("Btrfs: sync log after logging new name")
CC: stable@vger.kernel.org # 4.19+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-13 22:15:09 +01:00
Linus Torvalds
30fe0d07fd for-5.6-rc4-tag
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Merge tag 'for-5.6-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fix from David Sterba:
 "One fixup for DIO when in use with the new checksums, a missed case
  where the checksum size was still assuming u32"

* tag 'for-5.6-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: fix RAID direct I/O reads with alternate csums
2020-03-06 14:56:46 -06:00
Omar Sandoval
e7a04894c7 btrfs: fix RAID direct I/O reads with alternate csums
btrfs_lookup_and_bind_dio_csum() does pointer arithmetic which assumes
32-bit checksums. If using a larger checksum, this leads to spurious
failures when a direct I/O read crosses a stripe. This is easy
to reproduce:

  # mkfs.btrfs -f --checksum blake2 -d raid0 /dev/vdc /dev/vdd
  ...
  # mount /dev/vdc /mnt
  # cd /mnt
  # dd if=/dev/urandom of=foo bs=1M count=1 status=none
  # dd if=foo of=/dev/null bs=1M iflag=direct status=none
  dd: error reading 'foo': Input/output error
  # dmesg | tail -1
  [  135.821568] BTRFS warning (device vdc): csum failed root 5 ino 257 off 421888 ...

Fix it by using the actual checksum size.

Fixes: 1e25a2e3ca ("btrfs: don't assume ordered sums to be 4 bytes")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-03 15:26:08 +01:00
Linus Torvalds
d2eee25858 for-5.6-rc2-tag
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Merge tag 'for-5.6-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "These are fixes that were found during testing with help of error
  injection, plus some other stable material.

  There's a fixup to patch added to rc1 causing locking in wrong context
  warnings, tests found one more deadlock scenario. The patches are
  tagged for stable, two of them now in the queue but we'd like all
  three released at the same time.

  I'm not happy about fixes to fixes in such a fast succession during
  rcs, but I hope we found all the fallouts of commit 28553fa992
  ('Btrfs: fix race between shrinking truncate and fiemap')"

* tag 'for-5.6-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Btrfs: fix deadlock during fast fsync when logging prealloc extents beyond eof
  Btrfs: fix btrfs_wait_ordered_range() so that it waits for all ordered extents
  btrfs: fix bytes_may_use underflow in prealloc error condtition
  btrfs: handle logged extent failure properly
  btrfs: do not check delayed items are empty for single transaction cleanup
  btrfs: reset fs_root to NULL on error in open_ctree
  btrfs: destroy qgroup extent records on transaction abort
2020-02-23 09:43:50 -08:00
Filipe Manana
a5ae50dea9 Btrfs: fix deadlock during fast fsync when logging prealloc extents beyond eof
While logging the prealloc extents of an inode during a fast fsync we call
btrfs_truncate_inode_items(), through btrfs_log_prealloc_extents(), while
holding a read lock on a leaf of the inode's root (not the log root, the
fs/subvol root), and then that function locks the file range in the inode's
iotree. This can lead to a deadlock when:

* the fsync is ranged

* the file has prealloc extents beyond eof

* writeback for a range different from the fsync range starts
  during the fsync

* the size of the file is not sector size aligned

Because when finishing an ordered extent we lock first a file range and
then try to COW the fs/subvol tree to insert an extent item.

The following diagram shows how the deadlock can happen.

           CPU 1                                        CPU 2

  btrfs_sync_file()
    --> for range [0, 1MiB)

    --> inode has a size of
        1MiB and has 1 prealloc
        extent beyond the
        i_size, starting at offset
        4MiB

    flushes all delalloc for the
    range [0MiB, 1MiB) and waits
    for the respective ordered
    extents to complete

                                              --> before task at CPU 1 locks the
                                                  inode, a write into file range
                                                  [1MiB, 2MiB + 1KiB) is made

                                              --> i_size is updated to 2MiB + 1KiB

                                              --> writeback is started for that
                                                  range, [1MiB, 2MiB + 4KiB)
                                                  --> end offset rounded up to
                                                      be sector size aligned

    btrfs_log_dentry_safe()
      btrfs_log_inode_parent()
        btrfs_log_inode()

          btrfs_log_changed_extents()
            btrfs_log_prealloc_extents()
              --> does a search on the
                  inode's root
              --> holds a read lock on
                  leaf X

                                              btrfs_finish_ordered_io()
                                                --> locks range [1MiB, 2MiB + 4KiB)
                                                    --> end offset rounded up
                                                        to be sector size aligned

                                                --> tries to cow leaf X, through
                                                    insert_reserved_file_extent()
                                                    --> already locked by the
                                                        task at CPU 1

              btrfs_truncate_inode_items()

                --> gets an i_size of
                    2MiB + 1KiB, which is
                    not sector size
                    aligned

                --> tries to lock file
                    range [2MiB, (u64)-1)
                    --> the start range
                        is rounded down
                        from 2MiB + 1K
                        to 2MiB to be sector
                        size aligned

                    --> but the subrange
                        [2MiB, 2MiB + 4KiB) is
                        already locked by
                        task at CPU 2 which
                        is waiting to get a
                        write lock on leaf X
                        for which we are
                        holding a read lock

                                *** deadlock ***

This results in a stack trace like the following, triggered by test case
generic/561 from fstests:

  [ 2779.973608] INFO: task kworker/u8:6:247 blocked for more than 120 seconds.
  [ 2779.979536]       Not tainted 5.6.0-rc2-btrfs-next-53 #1
  [ 2779.984503] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [ 2779.990136] kworker/u8:6    D    0   247      2 0x80004000
  [ 2779.990457] Workqueue: btrfs-endio-write btrfs_work_helper [btrfs]
  [ 2779.990466] Call Trace:
  [ 2779.990491]  ? __schedule+0x384/0xa30
  [ 2779.990521]  schedule+0x33/0xe0
  [ 2779.990616]  btrfs_tree_read_lock+0x19e/0x2e0 [btrfs]
  [ 2779.990632]  ? remove_wait_queue+0x60/0x60
  [ 2779.990730]  btrfs_read_lock_root_node+0x2f/0x40 [btrfs]
  [ 2779.990782]  btrfs_search_slot+0x510/0x1000 [btrfs]
  [ 2779.990869]  btrfs_lookup_file_extent+0x4a/0x70 [btrfs]
  [ 2779.990944]  __btrfs_drop_extents+0x161/0x1060 [btrfs]
  [ 2779.990987]  ? mark_held_locks+0x6d/0xc0
  [ 2779.990994]  ? __slab_alloc.isra.49+0x99/0x100
  [ 2779.991060]  ? insert_reserved_file_extent.constprop.19+0x64/0x300 [btrfs]
  [ 2779.991145]  insert_reserved_file_extent.constprop.19+0x97/0x300 [btrfs]
  [ 2779.991222]  ? start_transaction+0xdd/0x5c0 [btrfs]
  [ 2779.991291]  btrfs_finish_ordered_io+0x4f4/0x840 [btrfs]
  [ 2779.991405]  btrfs_work_helper+0xaa/0x720 [btrfs]
  [ 2779.991432]  process_one_work+0x26d/0x6a0
  [ 2779.991460]  worker_thread+0x4f/0x3e0
  [ 2779.991481]  ? process_one_work+0x6a0/0x6a0
  [ 2779.991489]  kthread+0x103/0x140
  [ 2779.991499]  ? kthread_create_worker_on_cpu+0x70/0x70
  [ 2779.991515]  ret_from_fork+0x3a/0x50
  (...)
  [ 2780.026211] INFO: task fsstress:17375 blocked for more than 120 seconds.
  [ 2780.027480]       Not tainted 5.6.0-rc2-btrfs-next-53 #1
  [ 2780.028482] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [ 2780.030035] fsstress        D    0 17375  17373 0x00004000
  [ 2780.030038] Call Trace:
  [ 2780.030044]  ? __schedule+0x384/0xa30
  [ 2780.030052]  schedule+0x33/0xe0
  [ 2780.030075]  lock_extent_bits+0x20c/0x320 [btrfs]
  [ 2780.030094]  ? btrfs_truncate_inode_items+0xf4/0x1150 [btrfs]
  [ 2780.030098]  ? rcu_read_lock_sched_held+0x59/0xa0
  [ 2780.030102]  ? remove_wait_queue+0x60/0x60
  [ 2780.030122]  btrfs_truncate_inode_items+0x133/0x1150 [btrfs]
  [ 2780.030151]  ? btrfs_set_path_blocking+0xb2/0x160 [btrfs]
  [ 2780.030165]  ? btrfs_search_slot+0x379/0x1000 [btrfs]
  [ 2780.030195]  btrfs_log_changed_extents.isra.8+0x841/0x93e [btrfs]
  [ 2780.030202]  ? do_raw_spin_unlock+0x49/0xc0
  [ 2780.030215]  ? btrfs_get_num_csums+0x10/0x10 [btrfs]
  [ 2780.030239]  btrfs_log_inode+0xf83/0x1124 [btrfs]
  [ 2780.030251]  ? __mutex_unlock_slowpath+0x45/0x2a0
  [ 2780.030275]  btrfs_log_inode_parent+0x2a0/0xe40 [btrfs]
  [ 2780.030282]  ? dget_parent+0xa1/0x370
  [ 2780.030309]  btrfs_log_dentry_safe+0x4a/0x70 [btrfs]
  [ 2780.030329]  btrfs_sync_file+0x3f3/0x490 [btrfs]
  [ 2780.030339]  do_fsync+0x38/0x60
  [ 2780.030343]  __x64_sys_fdatasync+0x13/0x20
  [ 2780.030345]  do_syscall_64+0x5c/0x280
  [ 2780.030348]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [ 2780.030356] RIP: 0033:0x7f2d80f6d5f0
  [ 2780.030361] Code: Bad RIP value.
  [ 2780.030362] RSP: 002b:00007ffdba3c8548 EFLAGS: 00000246 ORIG_RAX: 000000000000004b
  [ 2780.030364] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f2d80f6d5f0
  [ 2780.030365] RDX: 00007ffdba3c84b0 RSI: 00007ffdba3c84b0 RDI: 0000000000000003
  [ 2780.030367] RBP: 000000000000004a R08: 0000000000000001 R09: 00007ffdba3c855c
  [ 2780.030368] R10: 0000000000000078 R11: 0000000000000246 R12: 00000000000001f4
  [ 2780.030369] R13: 0000000051eb851f R14: 00007ffdba3c85f0 R15: 0000557a49220d90

So fix this by making btrfs_truncate_inode_items() not lock the range in
the inode's iotree when the target root is a log root, since it's not
needed to lock the range for log roots as the protection from the inode's
lock and log_mutex are all that's needed.

Fixes: 28553fa992 ("Btrfs: fix race between shrinking truncate and fiemap")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-21 16:21:19 +01:00
Filipe Manana
e75fd33b3f Btrfs: fix btrfs_wait_ordered_range() so that it waits for all ordered extents
In btrfs_wait_ordered_range() once we find an ordered extent that has
finished with an error we exit the loop and don't wait for any other
ordered extents that might be still in progress.

All the users of btrfs_wait_ordered_range() expect that there are no more
ordered extents in progress after that function returns. So past fixes
such like the ones from the two following commits:

  ff612ba784 ("btrfs: fix panic during relocation after ENOSPC before
                   writeback happens")

  28aeeac1dd ("Btrfs: fix panic when starting bg cache writeout after
                   IO error")

don't work when there are multiple ordered extents in the range.

Fix that by making btrfs_wait_ordered_range() wait for all ordered extents
even after it finds one that had an error.

Link: https://github.com/kdave/btrfs-progs/issues/228#issuecomment-569777554
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-19 00:39:08 +01:00
Josef Bacik
b778cf962d btrfs: fix bytes_may_use underflow in prealloc error condtition
I hit the following warning while running my error injection stress
testing:

  WARNING: CPU: 3 PID: 1453 at fs/btrfs/space-info.h:108 btrfs_free_reserved_data_space_noquota+0xfd/0x160 [btrfs]
  RIP: 0010:btrfs_free_reserved_data_space_noquota+0xfd/0x160 [btrfs]
  Call Trace:
  btrfs_free_reserved_data_space+0x4f/0x70 [btrfs]
  __btrfs_prealloc_file_range+0x378/0x470 [btrfs]
  elfcorehdr_read+0x40/0x40
  ? elfcorehdr_read+0x40/0x40
  ? btrfs_commit_transaction+0xca/0xa50 [btrfs]
  ? dput+0xb4/0x2a0
  ? btrfs_log_dentry_safe+0x55/0x70 [btrfs]
  ? btrfs_sync_file+0x30e/0x420 [btrfs]
  ? do_fsync+0x38/0x70
  ? __x64_sys_fdatasync+0x13/0x20
  ? do_syscall_64+0x5b/0x1b0
  ? entry_SYSCALL_64_after_hwframe+0x44/0xa9

This happens if we fail to insert our reserved file extent.  At this
point we've already converted our reservation from ->bytes_may_use to
->bytes_reserved.  However once we break we will attempt to free
everything from [cur_offset, end] from ->bytes_may_use, but our extent
reservation will overlap part of this.

Fix this problem by adding ins.offset (our extent allocation size) to
cur_offset so we remove the actual remaining part from ->bytes_may_use.

I validated this fix using my inject-error.py script

python inject-error.py -o should_fail_bio -t cache_save_setup -t \
	__btrfs_prealloc_file_range \
	-t insert_reserved_file_extent.constprop.0 \
	-r "-5" ./run-fsstress.sh

where run-fsstress.sh simply mounts and runs fsstress on a disk.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-19 00:39:08 +01:00
Josef Bacik
bd727173e4 btrfs: handle logged extent failure properly
If we're allocating a logged extent we attempt to insert an extent
record for the file extent directly.  We increase
space_info->bytes_reserved, because the extent entry addition will call
btrfs_update_block_group(), which will convert the ->bytes_reserved to
->bytes_used.  However if we fail at any point while inserting the
extent entry we will bail and leave space on ->bytes_reserved, which
will trigger a WARN_ON() on umount.  Fix this by pinning the space if we
fail to insert, which is what happens in every other failure case that
involves adding the extent entry.

CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-19 00:39:08 +01:00
Josef Bacik
1e90315149 btrfs: do not check delayed items are empty for single transaction cleanup
btrfs_assert_delayed_root_empty() will check if the delayed root is
completely empty, but this is a filesystem-wide check.  On cleanup we
may have allowed other transactions to begin, for whatever reason, and
thus the delayed root is not empty.

So remove this check from cleanup_one_transation().  This however can
stay in btrfs_cleanup_transaction(), because it checks only after all of
the transactions have been properly cleaned up, and thus is valid.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-19 00:36:41 +01:00
Josef Bacik
315bf8ef91 btrfs: reset fs_root to NULL on error in open_ctree
While running my error injection script I hit a panic when we tried to
clean up the fs_root when freeing the fs_root.  This is because
fs_info->fs_root == PTR_ERR(-EIO), which isn't great.  Fix this by
setting fs_info->fs_root = NULL; if we fail to read the root.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-19 00:36:35 +01:00
Jeff Mahoney
81f7eb00ff btrfs: destroy qgroup extent records on transaction abort
We clean up the delayed references when we abort a transaction but we
leave the pending qgroup extent records behind, leaking memory.

This patch destroys the extent records when we destroy the delayed refs
and makes sure ensure they're gone before releasing the transaction.

Fixes: 3368d001ba ("btrfs: qgroup: Record possible quota-related extent for qgroup.")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
[ Rebased to latest upstream, remove to_qgroup() helper, use
  rbtree_postorder_for_each_entry_safe() wrapper ]
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-19 00:35:54 +01:00
Linus Torvalds
eaea294706 for-5.6-rc1-tag
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Merge tag 'for-5.6-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fix from David Sterba:
 "This is the fix for sleeping in a locked section bug reported by Dave
  Jones, caused by a patch dependence in development and pulled
  branches.

  I picked the existing patch over the fixup that Filipe sent, as it's a
  bit more generic fix. I've verified it with a specific test case, some
  rsync stress and one round of fstests"

* tag 'for-5.6-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: don't set path->leave_spinning for truncate
2020-02-17 13:26:30 -08:00
Josef Bacik
52e29e3310 btrfs: don't set path->leave_spinning for truncate
The only time we actually leave the path spinning is if we're truncating
a small amount and don't actually free an extent, which is not a common
occurrence.  We have to set the path blocking in order to add the
delayed ref anyway, so the first extent we find we set the path to
blocking and stay blocking for the duration of the operation.  With the
upcoming file extent map stuff there will be another case that we have
to have the path blocking, so just swap to blocking always.

Note: this patch also fixes a warning after 28553fa992 ("Btrfs: fix
race between shrinking truncate and fiemap") got merged that inserts
extent locks around truncation so the path must not leave spinning locks
after btrfs_search_slot.

  [70.794783] BUG: sleeping function called from invalid context at mm/slab.h:565
  [70.794834] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1141, name: rsync
  [70.794863] 5 locks held by rsync/1141:
  [70.794876]  #0: ffff888417b9c408 (sb_writers#17){.+.+}, at: mnt_want_write+0x20/0x50
  [70.795030]  #1: ffff888428de28e8 (&type->i_mutex_dir_key#13/1){+.+.}, at: lock_rename+0xf1/0x100
  [70.795051]  #2: ffff888417b9c608 (sb_internal#2){.+.+}, at: start_transaction+0x394/0x560
  [70.795124]  #3: ffff888403081768 (btrfs-fs-01){++++}, at: btrfs_try_tree_write_lock+0x2f/0x160
  [70.795203]  #4: ffff888403086568 (btrfs-fs-00){++++}, at: btrfs_try_tree_write_lock+0x2f/0x160
  [70.795222] CPU: 5 PID: 1141 Comm: rsync Not tainted 5.6.0-rc2-backup+ #2
  [70.795362] Call Trace:
  [70.795374]  dump_stack+0x71/0xa0
  [70.795445]  ___might_sleep.part.96.cold.106+0xa6/0xb6
  [70.795459]  kmem_cache_alloc+0x1d3/0x290
  [70.795471]  alloc_extent_state+0x22/0x1c0
  [70.795544]  __clear_extent_bit+0x3ba/0x580
  [70.795557]  ? _raw_spin_unlock_irq+0x24/0x30
  [70.795569]  btrfs_truncate_inode_items+0x339/0xe50
  [70.795647]  btrfs_evict_inode+0x269/0x540
  [70.795659]  ? dput.part.38+0x29/0x460
  [70.795671]  evict+0xcd/0x190
  [70.795682]  __dentry_kill+0xd6/0x180
  [70.795754]  dput.part.38+0x2ad/0x460
  [70.795765]  do_renameat2+0x3cb/0x540
  [70.795777]  __x64_sys_rename+0x1c/0x20

Reported-by: Dave Jones <davej@codemonkey.org.uk>
Fixes: 28553fa992 ("Btrfs: fix race between shrinking truncate and fiemap")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add note ]
Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-17 16:23:06 +01:00
Linus Torvalds
713db35604 for-5.6-rc1-tag
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Merge tag 'for-5.6-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "Two races fixed, memory leak fix, sysfs directory fixup and two new
  log messages:

   - two fixed race conditions: extent map merging and truncate vs
     fiemap

   - create the right sysfs directory with device information and move
     the individual device dirs under it

   - print messages when the tree-log is replayed at mount time or
     cannot be replayed on remount"

* tag 'for-5.6-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: sysfs, move device id directories to UUID/devinfo
  btrfs: sysfs, add UUID/devinfo kobject
  Btrfs: fix race between shrinking truncate and fiemap
  btrfs: log message when rw remount is attempted with unclean tree-log
  btrfs: print message when tree-log replay starts
  Btrfs: fix race between using extent maps and merging them
  btrfs: ref-verify: fix memory leaks
2020-02-16 11:43:45 -08:00
Anand Jain
1b9867eb61 btrfs: sysfs, move device id directories to UUID/devinfo
Originally it was planned to create device id directories under
UUID/devinfo, but it got under UUID/devices by mistake. We really want
it under definfo so the bare device node names are not mixed with device
ids and are easy to enumerate.

Fixes: 668e48af7a ("btrfs: sysfs, add devid/dev_state kobject and device attributes")
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-12 18:28:22 +01:00
Anand Jain
a013d141ec btrfs: sysfs, add UUID/devinfo kobject
Create directory /sys/fs/btrfs/UUID/devinfo to hold devices directories
by the id (unlike /devices).

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-12 18:28:18 +01:00
Filipe Manana
28553fa992 Btrfs: fix race between shrinking truncate and fiemap
When there is a fiemap executing in parallel with a shrinking truncate
we can end up in a situation where we have extent maps for which we no
longer have corresponding file extent items. This is generally harmless
and at the moment the only consequences are missing file extent items
representing holes after we expand the file size again after the
truncate operation removed the prealloc extent items, and stale
information for future fiemap calls (reporting extents that no longer
exist or may have been reallocated to other files for example).

Consider the following example:

1) Our inode has a size of 128KiB, one 128KiB extent at file offset 0
   and a 1MiB prealloc extent at file offset 128KiB;

2) Task A starts doing a shrinking truncate of our inode to reduce it to
   a size of 64KiB. Before it searches the subvolume tree for file
   extent items to delete, it drops all the extent maps in the range
   from 64KiB to (u64)-1 by calling btrfs_drop_extent_cache();

3) Task B starts doing a fiemap against our inode. When looking up for
   the inode's extent maps in the range from 128KiB to (u64)-1, it
   doesn't find any in the inode's extent map tree, since they were
   removed by task A.  Because it didn't find any in the extent map
   tree, it scans the inode's subvolume tree for file extent items, and
   it finds the 1MiB prealloc extent at file offset 128KiB, then it
   creates an extent map based on that file extent item and adds it to
   inode's extent map tree (this ends up being done by
   btrfs_get_extent() <- btrfs_get_extent_fiemap() <-
   get_extent_skip_holes());

4) Task A then drops the prealloc extent at file offset 128KiB and
   shrinks the 128KiB extent file offset 0 to a length of 64KiB. The
   truncation operation finishes and we end up with an extent map
   representing a 1MiB prealloc extent at file offset 128KiB, despite we
   don't have any more that extent;

After this the two types of problems we have are:

1) Future calls to fiemap always report that a 1MiB prealloc extent
   exists at file offset 128KiB. This is stale information, no longer
   correct;

2) If the size of the file is increased, by a truncate operation that
   increases the file size or by a write into a file offset > 64KiB for
   example, we end up not inserting file extent items to represent holes
   for any range between 128KiB and 128KiB + 1MiB, since the hole
   expansion function, btrfs_cont_expand() will skip hole insertion for
   any range for which an extent map exists that represents a prealloc
   extent. This causes fsck to complain about missing file extent items
   when not using the NO_HOLES feature.

The second issue could be often triggered by test case generic/561 from
fstests, which runs fsstress and duperemove in parallel, and duperemove
does frequent fiemap calls.

Essentially the problems happens because fiemap does not acquire the
inode's lock while truncate does, and fiemap locks the file range in the
inode's iotree while truncate does not. So fix the issue by making
btrfs_truncate_inode_items() lock the file range from the new file size
to (u64)-1, so that it serializes with fiemap.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-12 17:17:10 +01:00
David Sterba
10a3a3edc5 btrfs: log message when rw remount is attempted with unclean tree-log
A remount to a read-write filesystem is not safe when there's tree-log
to be replayed. Files that could be opened until now might be affected
by the changes in the tree-log.

A regular mount is needed to replay the log so the filesystem presents
the consistent view with the pending changes included.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-12 17:17:00 +01:00
David Sterba
e8294f2f6a btrfs: print message when tree-log replay starts
There's no logged information about tree-log replay although this is
something that points to previous unclean unmount. Other filesystems
report that as well.

Suggested-by: Chris Murphy <lists@colorremedies.com>
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-12 17:16:57 +01:00
Filipe Manana
ac05ca913e Btrfs: fix race between using extent maps and merging them
We have a few cases where we allow an extent map that is in an extent map
tree to be merged with other extents in the tree. Such cases include the
unpinning of an extent after the respective ordered extent completed or
after logging an extent during a fast fsync. This can lead to subtle and
dangerous problems because when doing the merge some other task might be
using the same extent map and as consequence see an inconsistent state of
the extent map - for example sees the new length but has seen the old start
offset.

With luck this triggers a BUG_ON(), and not some silent bug, such as the
following one in __do_readpage():

  $ cat -n fs/btrfs/extent_io.c
  3061  static int __do_readpage(struct extent_io_tree *tree,
  3062                           struct page *page,
  (...)
  3127                  em = __get_extent_map(inode, page, pg_offset, cur,
  3128                                        end - cur + 1, get_extent, em_cached);
  3129                  if (IS_ERR_OR_NULL(em)) {
  3130                          SetPageError(page);
  3131                          unlock_extent(tree, cur, end);
  3132                          break;
  3133                  }
  3134                  extent_offset = cur - em->start;
  3135                  BUG_ON(extent_map_end(em) <= cur);
  (...)

Consider the following example scenario, where we end up hitting the
BUG_ON() in __do_readpage().

We have an inode with a size of 8KiB and 2 extent maps:

  extent A: file offset 0, length 4KiB, disk_bytenr = X, persisted on disk by
            a previous transaction

  extent B: file offset 4KiB, length 4KiB, disk_bytenr = X + 4KiB, not yet
            persisted but writeback started for it already. The extent map
	    is pinned since there's writeback and an ordered extent in
	    progress, so it can not be merged with extent map A yet

The following sequence of steps leads to the BUG_ON():

1) The ordered extent for extent B completes, the respective page gets its
   writeback bit cleared and the extent map is unpinned, at that point it
   is not yet merged with extent map A because it's in the list of modified
   extents;

2) Due to memory pressure, or some other reason, the MM subsystem releases
   the page corresponding to extent B - btrfs_releasepage() is called and
   returns 1, meaning the page can be released as it's not dirty, not under
   writeback anymore and the extent range is not locked in the inode's
   iotree. However the extent map is not released, either because we are
   not in a context that allows memory allocations to block or because the
   inode's size is smaller than 16MiB - in this case our inode has a size
   of 8KiB;

3) Task B needs to read extent B and ends up __do_readpage() through the
   btrfs_readpage() callback. At __do_readpage() it gets a reference to
   extent map B;

4) Task A, doing a fast fsync, calls clear_em_loggin() against extent map B
   while holding the write lock on the inode's extent map tree - this
   results in try_merge_map() being called and since it's possible to merge
   extent map B with extent map A now (the extent map B was removed from
   the list of modified extents), the merging begins - it sets extent map
   B's start offset to 0 (was 4KiB), but before it increments the map's
   length to 8KiB (4kb + 4KiB), task A is at:

   BUG_ON(extent_map_end(em) <= cur);

   The call to extent_map_end() sees the extent map has a start of 0
   and a length still at 4KiB, so it returns 4KiB and 'cur' is 4KiB, so
   the BUG_ON() is triggered.

So it's dangerous to modify an extent map that is in the tree, because some
other task might have got a reference to it before and still using it, and
needs to see a consistent map while using it. Generally this is very rare
since most paths that lookup and use extent maps also have the file range
locked in the inode's iotree. The fsync path is pretty much the only
exception where we don't do it to avoid serialization with concurrent
reads.

Fix this by not allowing an extent map do be merged if if it's being used
by tasks other then the one attempting to merge the extent map (when the
reference count of the extent map is greater than 2).

Reported-by: ryusuke1925 <st13s20@gm.ibaraki-ct.ac.jp>
Reported-by: Koki Mitani <koki.mitani.xg@hco.ntt.co.jp>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=206211
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-12 17:16:46 +01:00
Wenwen Wang
f311ade3a7 btrfs: ref-verify: fix memory leaks
In btrfs_ref_tree_mod(), 'ref' and 'ra' are allocated through kzalloc() and
kmalloc(), respectively. In the following code, if an error occurs, the
execution will be redirected to 'out' or 'out_unlock' and the function will
be exited. However, on some of the paths, 'ref' and 'ra' are not
deallocated, leading to memory leaks. For example, if 'action' is
BTRFS_ADD_DELAYED_EXTENT, add_block_entry() will be invoked. If the return
value indicates an error, the execution will be redirected to 'out'. But,
'ref' is not deallocated on this path, causing a memory leak.

To fix the above issues, deallocate both 'ref' and 'ra' before exiting from
the function when an error is encountered.

CC: stable@vger.kernel.org # 4.15+
Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-12 17:16:31 +01:00
Linus Torvalds
ad80142836 for-5.6-tag
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Merge tag 'for-5.6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull more btrfs updates from David Sterba:
 "Fixes that arrived after the merge window freeze, mostly stable
  material.

   - fix race in tree-mod-log element tracking

   - fix bio flushing inside extent writepages

   - fix assertion when in-memory tracking of discarded extents finds an
     empty tree (eg. after adding a new device)

   - update logic of temporary read-only block groups to take into
     account overcommit

   - fix some fixup worker corner cases:
       - page could not go through proper COW cycle and the dirty status
         is lost due to page migration
       - deadlock if delayed allocation is performed under page lock

   - fix send emitting invalid clones within the same file

   - fix statfs reporting 0 free space when global block reserve size is
     larger than remaining free space but there is still space for new
     chunks"

* tag 'for-5.6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: do not zero f_bavail if we have available space
  Btrfs: send, fix emission of invalid clone operations within the same file
  btrfs: do not do delalloc reservation under page lock
  btrfs: drop the -EBUSY case in __extent_writepage_io
  Btrfs: keep pages dirty when using btrfs_writepage_fixup_worker
  btrfs: take overcommit into account in inc_block_group_ro
  btrfs: fix force usage in inc_block_group_ro
  btrfs: Correctly handle empty trees in find_first_clear_extent_bit
  btrfs: flush write bio if we loop in extent_write_cache_pages
  Btrfs: fix race between adding and putting tree mod seq elements and nodes
2020-02-03 17:03:42 +00:00
Josef Bacik
d55966c427 btrfs: do not zero f_bavail if we have available space
There was some logic added a while ago to clear out f_bavail in statfs()
if we did not have enough free metadata space to satisfy our global
reserve.  This was incorrect at the time, however didn't really pose a
problem for normal file systems because we would often allocate chunks
if we got this low on free metadata space, and thus wouldn't really hit
this case unless we were actually full.

Fast forward to today and now we are much better about not allocating
metadata chunks all of the time.  Couple this with d792b0f197 ("btrfs:
always reserve our entire size for the global reserve") which now means
we'll easily have a larger global reserve than our free space, we are
now more likely to trip over this while still having plenty of space.

Fix this by skipping this logic if the global rsv's space_info is not
full.  space_info->full is 0 unless we've attempted to allocate a chunk
for that space_info and that has failed.  If this happens then the space
for the global reserve is definitely sacred and we need to report
b_avail == 0, but before then we can just use our calculated b_avail.

Reported-by: Martin Steigerwald <martin@lichtvoll.de>
Fixes: ca8a51b3a9 ("btrfs: statfs: report zero available if metadata are exhausted")
CC: stable@vger.kernel.org # 4.5+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Tested-By: Martin Steigerwald <martin@lichtvoll.de>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-02-02 18:49:32 +01:00
Mikhail Zaslonko
3fd396afc0 btrfs: use larger zlib buffer for s390 hardware compression
In order to benefit from s390 zlib hardware compression support,
increase the btrfs zlib workspace buffer size from 1 to 4 pages (if s390
zlib hardware support is enabled on the machine).

This brings up to 60% better performance in hardware on s390 compared to
the PAGE_SIZE buffer and much more compared to the software zlib
processing in btrfs.  In case of memory pressure, fall back to a single
page buffer during workspace allocation.

The data compressed with larger input buffers will still conform to zlib
standard and thus can be decompressed also on a systems that uses only
PAGE_SIZE buffer for btrfs zlib.

Link: http://lkml.kernel.org/r/20200108105103.29028-1-zaslonko@linux.ibm.com
Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Eduard Shishkin <edward6@linux.ibm.com>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-01-31 10:30:40 -08:00
Filipe Manana
9722b10148 Btrfs: send, fix emission of invalid clone operations within the same file
When doing an incremental send and a file has extents shared with itself
at different file offsets, it's possible for send to emit clone operations
that will fail at the destination because the source range goes beyond the
file's current size. This happens when the file size has increased in the
send snapshot, there is a hole between the shared extents and both shared
extents are at file offsets which are greater the file's size in the
parent snapshot.

Example:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt/sdb

  $ xfs_io -f -c "pwrite -S 0xf1 0 64K" /mnt/sdb/foobar
  $ btrfs subvolume snapshot -r /mnt/sdb /mnt/sdb/base
  $ btrfs send -f /tmp/1.snap /mnt/sdb/base

  # Create a 320K extent at file offset 512K.
  $ xfs_io -c "pwrite -S 0xab 512K 64K" /mnt/sdb/foobar
  $ xfs_io -c "pwrite -S 0xcd 576K 64K" /mnt/sdb/foobar
  $ xfs_io -c "pwrite -S 0xef 640K 64K" /mnt/sdb/foobar
  $ xfs_io -c "pwrite -S 0x64 704K 64K" /mnt/sdb/foobar
  $ xfs_io -c "pwrite -S 0x73 768K 64K" /mnt/sdb/foobar

  # Clone part of that 320K extent into a lower file offset (192K).
  # This file offset is greater than the file's size in the parent
  # snapshot (64K). Also the clone range is a bit behind the offset of
  # the 320K extent so that we leave a hole between the shared extents.
  $ xfs_io -c "reflink /mnt/sdb/foobar 448K 192K 192K" /mnt/sdb/foobar

  $ btrfs subvolume snapshot -r /mnt/sdb /mnt/sdb/incr
  $ btrfs send -p /mnt/sdb/base -f /tmp/2.snap /mnt/sdb/incr

  $ mkfs.btrfs -f /dev/sdc
  $ mount /dev/sdc /mnt/sdc

  $ btrfs receive -f /tmp/1.snap /mnt/sdc
  $ btrfs receive -f /tmp/2.snap /mnt/sdc
  ERROR: failed to clone extents to foobar: Invalid argument

The problem is that after processing the extent at file offset 256K, which
refers to the first 128K of the 320K extent created by the buffered write
operations, we have 'cur_inode_next_write_offset' set to 384K, which
corresponds to the end offset of the partially shared extent (256K + 128K)
and to the current file size in the receiver. Then when we process the
extent at offset 512K, we do extent backreference iteration to figure out
if we can clone the extent from some other inode or from the same inode,
and we consider the extent at offset 256K of the same inode as a valid
source for a clone operation, which is not correct because at that point
the current file size in the receiver is 384K, which corresponds to the
end of last processed extent (at file offset 256K), so using a clone
source range from 256K to 256K + 320K is invalid because that goes past
the current size of the file (384K) - this makes the receiver get an
-EINVAL error when attempting the clone operation.

So fix this by excluding clone sources that have a range that goes beyond
the current file size in the receiver when iterating extent backreferences.

A test case for fstests follows soon.

Fixes: 11f2069c11 ("Btrfs: send, allow clone operations within the same file")
CC: stable@vger.kernel.org # 5.5+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-31 14:02:19 +01:00
Josef Bacik
f4b1363cae btrfs: do not do delalloc reservation under page lock
We ran into a deadlock in production with the fixup worker.  The stack
traces were as follows:

Thread responsible for the writeout, waiting on the page lock

  [<0>] io_schedule+0x12/0x40
  [<0>] __lock_page+0x109/0x1e0
  [<0>] extent_write_cache_pages+0x206/0x360
  [<0>] extent_writepages+0x40/0x60
  [<0>] do_writepages+0x31/0xb0
  [<0>] __writeback_single_inode+0x3d/0x350
  [<0>] writeback_sb_inodes+0x19d/0x3c0
  [<0>] __writeback_inodes_wb+0x5d/0xb0
  [<0>] wb_writeback+0x231/0x2c0
  [<0>] wb_workfn+0x308/0x3c0
  [<0>] process_one_work+0x1e0/0x390
  [<0>] worker_thread+0x2b/0x3c0
  [<0>] kthread+0x113/0x130
  [<0>] ret_from_fork+0x35/0x40
  [<0>] 0xffffffffffffffff

Thread of the fixup worker who is holding the page lock

  [<0>] start_delalloc_inodes+0x241/0x2d0
  [<0>] btrfs_start_delalloc_roots+0x179/0x230
  [<0>] btrfs_alloc_data_chunk_ondemand+0x11b/0x2e0
  [<0>] btrfs_check_data_free_space+0x53/0xa0
  [<0>] btrfs_delalloc_reserve_space+0x20/0x70
  [<0>] btrfs_writepage_fixup_worker+0x1fc/0x2a0
  [<0>] normal_work_helper+0x11c/0x360
  [<0>] process_one_work+0x1e0/0x390
  [<0>] worker_thread+0x2b/0x3c0
  [<0>] kthread+0x113/0x130
  [<0>] ret_from_fork+0x35/0x40
  [<0>] 0xffffffffffffffff

Thankfully the stars have to align just right to hit this.  First you
have to end up in the fixup worker, which is tricky by itself (my
reproducer does DIO reads into a MMAP'ed region, so not a common
operation).  Then you have to have less than a page size of free data
space and 0 unallocated space so you go down the "commit the transaction
to free up pinned space" path.  This was accomplished by a random
balance that was running on the host.  Then you get this deadlock.

I'm still in the process of trying to force the deadlock to happen on
demand, but I've hit other issues.  I can still trigger the fixup worker
path itself so this patch has been tested in that regard, so the normal
case is fine.

Fixes: 87826df0ec ("btrfs: delalloc for page dirtied out-of-band in fixup worker")
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-31 14:02:15 +01:00
Josef Bacik
5ab5805569 btrfs: drop the -EBUSY case in __extent_writepage_io
Now that we only return 0 or -EAGAIN from btrfs_writepage_cow_fixup, we
do not need this -EBUSY case.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-31 14:02:11 +01:00
Chris Mason
25f3c50219 Btrfs: keep pages dirty when using btrfs_writepage_fixup_worker
For COW, btrfs expects pages dirty pages to have been through a few setup
steps.  This includes reserving space for the new block allocations and marking
the range in the state tree for delayed allocation.

A few places outside btrfs will dirty pages directly, especially when unmapping
mmap'd pages.  In order for these to properly go through COW, we run them
through a fixup worker to wait for stable pages, and do the delalloc prep.

87826df0ec added a window where the dirty pages were cleaned, but pending
more action from the fixup worker.  We clear_page_dirty_for_io() before
we call into writepage, so the page is no longer dirty.  The commit
changed it so now we leave the page clean between unlocking it here and
the fixup worker starting at some point in the future.

During this window, page migration can jump in and relocate the page.  Once our
fixup work actually starts, it finds page->mapping is NULL and we end up
freeing the page without ever writing it.

This leads to crc errors and other exciting problems, since it screws up the
whole statemachine for waiting for ordered extents.  The fix here is to keep
the page dirty while we're waiting for the fixup worker to get to work.
This is accomplished by returning -EAGAIN from btrfs_writepage_cow_fixup
if we queued the page up for fixup, which will cause the writepage
function to redirty the page.

Because we now expect the page to be dirty once it gets to the fixup
worker we must adjust the error cases to call clear_page_dirty_for_io()
on the page.  That is the bulk of the patch, but it is not the fix, the
fix is the -EAGAIN from btrfs_writepage_cow_fixup.  We cannot separate
these two changes out because the error conditions change with the new
expectations.

Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-31 14:02:08 +01:00
Josef Bacik
a30a3d2067 btrfs: take overcommit into account in inc_block_group_ro
inc_block_group_ro does a calculation to see if we have enough room left
over if we mark this block group as read only in order to see if it's ok
to mark the block group as read only.

The problem is this calculation _only_ works for data, where our used is
always less than our total.  For metadata we will overcommit, so this
will almost always fail for metadata.

Fix this by exporting btrfs_can_overcommit, and then see if we have
enough space to remove the remaining free space in the block group we
are trying to mark read only.  If we do then we can mark this block
group as read only.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-31 14:02:01 +01:00
Josef Bacik
a7a63acc65 btrfs: fix force usage in inc_block_group_ro
For some reason we've translated the do_chunk_alloc that goes into
btrfs_inc_block_group_ro to force in inc_block_group_ro, but these are
two different things.

force for inc_block_group_ro is used when we are forcing the block group
read only no matter what, for example when the underlying chunk is
marked read only.  We need to not do the space check here as this block
group needs to be read only.

btrfs_inc_block_group_ro() has a do_chunk_alloc flag that indicates that
we need to pre-allocate a chunk before marking the block group read
only.  This has nothing to do with forcing, and in fact we _always_ want
to do the space check in this case, so unconditionally pass false for
force in this case.

Then fixup inc_block_group_ro to honor force as it's expected and
documented to do.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-31 14:01:55 +01:00
Nikolay Borisov
5750c37523 btrfs: Correctly handle empty trees in find_first_clear_extent_bit
Raviu reported that running his regular fs_trim segfaulted with the
following backtrace:

[  237.525947] assertion failed: prev, in ../fs/btrfs/extent_io.c:1595
[  237.525984] ------------[ cut here ]------------
[  237.525985] kernel BUG at ../fs/btrfs/ctree.h:3117!
[  237.525992] invalid opcode: 0000 [#1] SMP PTI
[  237.525998] CPU: 4 PID: 4423 Comm: fstrim Tainted: G     U     OE     5.4.14-8-vanilla #1
[  237.526001] Hardware name: ASUSTeK COMPUTER INC.
[  237.526044] RIP: 0010:assfail.constprop.58+0x18/0x1a [btrfs]
[  237.526079] Call Trace:
[  237.526120]  find_first_clear_extent_bit+0x13d/0x150 [btrfs]
[  237.526148]  btrfs_trim_fs+0x211/0x3f0 [btrfs]
[  237.526184]  btrfs_ioctl_fitrim+0x103/0x170 [btrfs]
[  237.526219]  btrfs_ioctl+0x129a/0x2ed0 [btrfs]
[  237.526227]  ? filemap_map_pages+0x190/0x3d0
[  237.526232]  ? do_filp_open+0xaf/0x110
[  237.526238]  ? _copy_to_user+0x22/0x30
[  237.526242]  ? cp_new_stat+0x150/0x180
[  237.526247]  ? do_vfs_ioctl+0xa4/0x640
[  237.526278]  ? btrfs_ioctl_get_supported_features+0x30/0x30 [btrfs]
[  237.526283]  do_vfs_ioctl+0xa4/0x640
[  237.526288]  ? __do_sys_newfstat+0x3c/0x60
[  237.526292]  ksys_ioctl+0x70/0x80
[  237.526297]  __x64_sys_ioctl+0x16/0x20
[  237.526303]  do_syscall_64+0x5a/0x1c0
[  237.526310]  entry_SYSCALL_64_after_hwframe+0x49/0xbe

That was due to btrfs_fs_device::aloc_tree being empty. Initially I
thought this wasn't possible and as a percaution have put the assert in
find_first_clear_extent_bit. Turns out this is indeed possible and could
happen when a file system with SINGLE data/metadata profile has a 2nd
device added. Until balance is run or a new chunk is allocated on this
device it will be completely empty.

In this case find_first_clear_extent_bit should return the full range
[0, -1ULL] and let the caller handle this i.e for trim the end will be
capped at the size of actual device.

Link: https://lore.kernel.org/linux-btrfs/izW2WNyvy1dEDweBICizKnd2KDwDiDyY2EYQr4YCwk7pkuIpthx-JRn65MPBde00ND6V0_Lh8mW0kZwzDiLDv25pUYWxkskWNJnVP0kgdMA=@protonmail.com/
Fixes: 45bfcfc168 ("btrfs: Implement find_first_clear_extent_bit")
CC: stable@vger.kernel.org # 5.2+
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-31 14:01:29 +01:00
Josef Bacik
42ffb0bf58 btrfs: flush write bio if we loop in extent_write_cache_pages
There exists a deadlock with range_cyclic that has existed forever.  If
we loop around with a bio already built we could deadlock with a writer
who has the page locked that we're attempting to write but is waiting on
a page in our bio to be written out.  The task traces are as follows

  PID: 1329874  TASK: ffff889ebcdf3800  CPU: 33  COMMAND: "kworker/u113:5"
   #0 [ffffc900297bb658] __schedule at ffffffff81a4c33f
   #1 [ffffc900297bb6e0] schedule at ffffffff81a4c6e3
   #2 [ffffc900297bb6f8] io_schedule at ffffffff81a4ca42
   #3 [ffffc900297bb708] __lock_page at ffffffff811f145b
   #4 [ffffc900297bb798] __process_pages_contig at ffffffff814bc502
   #5 [ffffc900297bb8c8] lock_delalloc_pages at ffffffff814bc684
   #6 [ffffc900297bb900] find_lock_delalloc_range at ffffffff814be9ff
   #7 [ffffc900297bb9a0] writepage_delalloc at ffffffff814bebd0
   #8 [ffffc900297bba18] __extent_writepage at ffffffff814bfbf2
   #9 [ffffc900297bba98] extent_write_cache_pages at ffffffff814bffbd

  PID: 2167901  TASK: ffff889dc6a59c00  CPU: 14  COMMAND:
  "aio-dio-invalid"
   #0 [ffffc9003b50bb18] __schedule at ffffffff81a4c33f
   #1 [ffffc9003b50bba0] schedule at ffffffff81a4c6e3
   #2 [ffffc9003b50bbb8] io_schedule at ffffffff81a4ca42
   #3 [ffffc9003b50bbc8] wait_on_page_bit at ffffffff811f24d6
   #4 [ffffc9003b50bc60] prepare_pages at ffffffff814b05a7
   #5 [ffffc9003b50bcd8] btrfs_buffered_write at ffffffff814b1359
   #6 [ffffc9003b50bdb0] btrfs_file_write_iter at ffffffff814b5933
   #7 [ffffc9003b50be38] new_sync_write at ffffffff8128f6a8
   #8 [ffffc9003b50bec8] vfs_write at ffffffff81292b9d
   #9 [ffffc9003b50bf00] ksys_pwrite64 at ffffffff81293032

I used drgn to find the respective pages we were stuck on

page_entry.page 0xffffea00fbfc7500 index 8148 bit 15 pid 2167901
page_entry.page 0xffffea00f9bb7400 index 7680 bit 0 pid 1329874

As you can see the kworker is waiting for bit 0 (PG_locked) on index
7680, and aio-dio-invalid is waiting for bit 15 (PG_writeback) on index
8148.  aio-dio-invalid has 7680, and the kworker epd looks like the
following

  crash> struct extent_page_data ffffc900297bbbb0
  struct extent_page_data {
    bio = 0xffff889f747ed830,
    tree = 0xffff889eed6ba448,
    extent_locked = 0,
    sync_io = 0
  }

Probably worth mentioning as well that it waits for writeback of the
page to complete while holding a lock on it (at prepare_pages()).

Using drgn I walked the bio pages looking for page
0xffffea00fbfc7500 which is the one we're waiting for writeback on

  bio = Object(prog, 'struct bio', address=0xffff889f747ed830)
  for i in range(0, bio.bi_vcnt.value_()):
      bv = bio.bi_io_vec[i]
      if bv.bv_page.value_() == 0xffffea00fbfc7500:
	  print("FOUND IT")

which validated what I suspected.

The fix for this is simple, flush the epd before we loop back around to
the beginning of the file during writeout.

Fixes: b293f02e14 ("Btrfs: Add writepages support")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-31 14:01:25 +01:00
Filipe Manana
7227ff4de5 Btrfs: fix race between adding and putting tree mod seq elements and nodes
There is a race between adding and removing elements to the tree mod log
list and rbtree that can lead to use-after-free problems.

Consider the following example that explains how/why the problems happens:

1) Task A has mod log element with sequence number 200. It currently is
   the only element in the mod log list;

2) Task A calls btrfs_put_tree_mod_seq() because it no longer needs to
   access the tree mod log. When it enters the function, it initializes
   'min_seq' to (u64)-1. Then it acquires the lock 'tree_mod_seq_lock'
   before checking if there are other elements in the mod seq list.
   Since the list it empty, 'min_seq' remains set to (u64)-1. Then it
   unlocks the lock 'tree_mod_seq_lock';

3) Before task A acquires the lock 'tree_mod_log_lock', task B adds
   itself to the mod seq list through btrfs_get_tree_mod_seq() and gets a
   sequence number of 201;

4) Some other task, name it task C, modifies a btree and because there
   elements in the mod seq list, it adds a tree mod elem to the tree
   mod log rbtree. That node added to the mod log rbtree is assigned
   a sequence number of 202;

5) Task B, which is doing fiemap and resolving indirect back references,
   calls btrfs get_old_root(), with 'time_seq' == 201, which in turn
   calls tree_mod_log_search() - the search returns the mod log node
   from the rbtree with sequence number 202, created by task C;

6) Task A now acquires the lock 'tree_mod_log_lock', starts iterating
   the mod log rbtree and finds the node with sequence number 202. Since
   202 is less than the previously computed 'min_seq', (u64)-1, it
   removes the node and frees it;

7) Task B still has a pointer to the node with sequence number 202, and
   it dereferences the pointer itself and through the call to
   __tree_mod_log_rewind(), resulting in a use-after-free problem.

This issue can be triggered sporadically with the test case generic/561
from fstests, and it happens more frequently with a higher number of
duperemove processes. When it happens to me, it either freezes the VM or
it produces a trace like the following before crashing:

  [ 1245.321140] general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
  [ 1245.321200] CPU: 1 PID: 26997 Comm: pool Not tainted 5.5.0-rc6-btrfs-next-52 #1
  [ 1245.321235] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014
  [ 1245.321287] RIP: 0010:rb_next+0x16/0x50
  [ 1245.321307] Code: ....
  [ 1245.321372] RSP: 0018:ffffa151c4d039b0 EFLAGS: 00010202
  [ 1245.321388] RAX: 6b6b6b6b6b6b6b6b RBX: ffff8ae221363c80 RCX: 6b6b6b6b6b6b6b6b
  [ 1245.321409] RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff8ae221363c80
  [ 1245.321439] RBP: ffff8ae20fcc4688 R08: 0000000000000002 R09: 0000000000000000
  [ 1245.321475] R10: ffff8ae20b120910 R11: 00000000243f8bb1 R12: 0000000000000038
  [ 1245.321506] R13: ffff8ae221363c80 R14: 000000000000075f R15: ffff8ae223f762b8
  [ 1245.321539] FS:  00007fdee1ec7700(0000) GS:ffff8ae236c80000(0000) knlGS:0000000000000000
  [ 1245.321591] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [ 1245.321614] CR2: 00007fded4030c48 CR3: 000000021da16003 CR4: 00000000003606e0
  [ 1245.321642] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  [ 1245.321668] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  [ 1245.321706] Call Trace:
  [ 1245.321798]  __tree_mod_log_rewind+0xbf/0x280 [btrfs]
  [ 1245.321841]  btrfs_search_old_slot+0x105/0xd00 [btrfs]
  [ 1245.321877]  resolve_indirect_refs+0x1eb/0xc60 [btrfs]
  [ 1245.321912]  find_parent_nodes+0x3dc/0x11b0 [btrfs]
  [ 1245.321947]  btrfs_check_shared+0x115/0x1c0 [btrfs]
  [ 1245.321980]  ? extent_fiemap+0x59d/0x6d0 [btrfs]
  [ 1245.322029]  extent_fiemap+0x59d/0x6d0 [btrfs]
  [ 1245.322066]  do_vfs_ioctl+0x45a/0x750
  [ 1245.322081]  ksys_ioctl+0x70/0x80
  [ 1245.322092]  ? trace_hardirqs_off_thunk+0x1a/0x1c
  [ 1245.322113]  __x64_sys_ioctl+0x16/0x20
  [ 1245.322126]  do_syscall_64+0x5c/0x280
  [ 1245.322139]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [ 1245.322155] RIP: 0033:0x7fdee3942dd7
  [ 1245.322177] Code: ....
  [ 1245.322258] RSP: 002b:00007fdee1ec6c88 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
  [ 1245.322294] RAX: ffffffffffffffda RBX: 00007fded40210d8 RCX: 00007fdee3942dd7
  [ 1245.322314] RDX: 00007fded40210d8 RSI: 00000000c020660b RDI: 0000000000000004
  [ 1245.322337] RBP: 0000562aa89e7510 R08: 0000000000000000 R09: 00007fdee1ec6d44
  [ 1245.322369] R10: 0000000000000073 R11: 0000000000000246 R12: 00007fdee1ec6d48
  [ 1245.322390] R13: 00007fdee1ec6d40 R14: 00007fded40210d0 R15: 00007fdee1ec6d50
  [ 1245.322423] Modules linked in: ....
  [ 1245.323443] ---[ end trace 01de1e9ec5dff3cd ]---

Fix this by ensuring that btrfs_put_tree_mod_seq() computes the minimum
sequence number and iterates the rbtree while holding the lock
'tree_mod_log_lock' in write mode. Also get rid of the 'tree_mod_seq_lock'
lock, since it is now redundant.

Fixes: bd989ba359 ("Btrfs: add tree modification log functions")
Fixes: 097b8a7c9e ("Btrfs: join tree mod log code with the code holding back delayed refs")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-31 14:01:20 +01:00
Linus Torvalds
b5f7ab6b1c fs-dedupe-last-block-tag
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Merge tag 'fs-dedupe-last-block-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull fs deduplication fix from David Sterba:
 "This is a fix for deduplication bug: the last block of two files is
  allowed to deduplicated. This got broken in 5.1 by lifting some
  generic checks to VFS layer. The affected filesystems are btrfs and
  xfs.

  The patches are marked for stable as the bug decreases deduplication
  effectivity"

* tag 'fs-dedupe-last-block-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Btrfs: make deduplication with range including the last block work
  fs: allow deduplication of eof block into the end of the destination file
2020-01-28 15:18:23 -08:00
Linus Torvalds
81a046b18b for-5.6-tag
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Merge tag 'for-5.6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs updates from David Sterba:
 "Features, highlights:

   - async discard
       - "mount -o discard=async" to enable it
       - freed extents are not discarded immediatelly, but grouped
         together and trimmed later, with IO rate limiting
       - the "sync" mode submits short extents that could have been
         ignored completely by the device, for SATA prior to 3.1 the
         requests are unqueued and have a big impact on performance
       - the actual discard IO requests have been moved out of
         transaction commit to a worker thread, improving commit latency
       - IO rate and request size can be tuned by sysfs files, for now
         enabled only with CONFIG_BTRFS_DEBUG as we might need to
         add/delete the files and don't have a stable-ish ABI for
         general use, defaults are conservative

   - export device state info in sysfs, eg. missing, writeable

   - no discard of extents known to be untouched on disk (eg. after
     reservation)

   - device stats reset is logged with process name and PID that called
     the ioctl

  Fixes:

   - fix missing hole after hole punching and fsync when using NO_HOLES

   - writeback: range cyclic mode could miss some dirty pages and lead
     to OOM

   - two more corner cases for metadata_uuid change after power loss
     during the change

   - fix infinite loop during fsync after mix of rename operations

  Core changes:

   - qgroup assign returns ENOTCONN when quotas not enabled, used to
     return EINVAL that was confusing

   - device closing does not need to allocate memory anymore

   - snapshot aware code got removed, disabled for years due to
     performance problems, reimplmentation will allow to select wheter
     defrag breaks or does not break COW on shared extents

   - tree-checker:
       - check leaf chunk item size, cross check against number of
         stripes
       - verify location keys for DIR_ITEM, DIR_INDEX and XATTR items

   - new self test for physical -> logical mapping code, used for super
     block range exclusion

   - assertion helpers/macros updated to avoid objtool "unreachable
     code" reports on older compilers or config option combinations"

* tag 'for-5.6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (84 commits)
  btrfs: free block groups after free'ing fs trees
  btrfs: Fix split-brain handling when changing FSID to metadata uuid
  btrfs: Handle another split brain scenario with metadata uuid feature
  btrfs: Factor out metadata_uuid code from find_fsid.
  btrfs: Call find_fsid from find_fsid_inprogress
  Btrfs: fix infinite loop during fsync after rename operations
  btrfs: set trans->drity in btrfs_commit_transaction
  btrfs: drop log root for dropped roots
  btrfs: sysfs, add devid/dev_state kobject and device attributes
  btrfs: Refactor btrfs_rmap_block to improve readability
  btrfs: Add self-tests for btrfs_rmap_block
  btrfs: selftests: Add support for dummy devices
  btrfs: Move and unexport btrfs_rmap_block
  btrfs: separate definition of assertion failure handlers
  btrfs: device stats, log when stats are zeroed
  btrfs: fix improper setting of scanned for range cyclic write cache pages
  btrfs: safely advance counter when looking up bio csums
  btrfs: remove unused member btrfs_device::work
  btrfs: remove unnecessary wrapper get_alloc_profile
  btrfs: add correction to handle -1 edge case in async discard
  ...
2020-01-28 14:53:31 -08:00
Linus Torvalds
c677124e63 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
 "These were the main changes in this cycle:

   - More -rt motivated separation of CONFIG_PREEMPT and
     CONFIG_PREEMPTION.

   - Add more low level scheduling topology sanity checks and warnings
     to filter out nonsensical topologies that break scheduling.

   - Extend uclamp constraints to influence wakeup CPU placement

   - Make the RT scheduler more aware of asymmetric topologies and CPU
     capacities, via uclamp metrics, if CONFIG_UCLAMP_TASK=y

   - Make idle CPU selection more consistent

   - Various fixes, smaller cleanups, updates and enhancements - please
     see the git log for details"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (58 commits)
  sched/fair: Define sched_idle_cpu() only for SMP configurations
  sched/topology: Assert non-NUMA topology masks don't (partially) overlap
  idle: fix spelling mistake "iterrupts" -> "interrupts"
  sched/fair: Remove redundant call to cpufreq_update_util()
  sched/psi: create /proc/pressure and /proc/pressure/{io|memory|cpu} only when psi enabled
  sched/fair: Fix sgc->{min,max}_capacity calculation for SD_OVERLAP
  sched/fair: calculate delta runnable load only when it's needed
  sched/cputime: move rq parameter in irqtime_account_process_tick
  stop_machine: Make stop_cpus() static
  sched/debug: Reset watchdog on all CPUs while processing sysrq-t
  sched/core: Fix size of rq::uclamp initialization
  sched/uclamp: Fix a bug in propagating uclamp value in new cgroups
  sched/fair: Load balance aggressively for SCHED_IDLE CPUs
  sched/fair : Improve update_sd_pick_busiest for spare capacity case
  watchdog: Remove soft_lockup_hrtimer_cnt and related code
  sched/rt: Make RT capacity-aware
  sched/fair: Make EAS wakeup placement consider uclamp restrictions
  sched/fair: Make task_fits_capacity() consider uclamp restrictions
  sched/uclamp: Rename uclamp_util_with() into uclamp_rq_util_with()
  sched/uclamp: Make uclamp util helpers use and return UL values
  ...
2020-01-28 10:07:09 -08:00
Linus Torvalds
a075f23dd4 for-5.5-rc8-tag
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Merge tag 'for-5.5-rc8-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fix from David Sterba:
 "Here's a last minute fix for a regression introduced in this
  development cycle.

  There's a small chance of a silent corruption when device replace and
  NOCOW data writes happen at the same time in one block group. Metadata
  or COW data writes are unaffected.

  The extra fixup patch is there to silence an unnecessary warning"

* tag 'for-5.5-rc8-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: dev-replace: remove warning for unknown return codes when finished
  btrfs: scrub: Require mandatory block group RO for dev-replace
2020-01-25 10:55:24 -08:00
David Sterba
4cea9037f8 btrfs: dev-replace: remove warning for unknown return codes when finished
The fstests btrfs/011 triggered a warning at the end of device replace,

  [ 1891.998975] BTRFS warning (device vdd): failed setting block group ro: -28
  [ 1892.038338] BTRFS error (device vdd): btrfs_scrub_dev(/dev/vdd, 1, /dev/vdb) failed -28
  [ 1892.059993] ------------[ cut here ]------------
  [ 1892.063032] WARNING: CPU: 2 PID: 2244 at fs/btrfs/dev-replace.c:506 btrfs_dev_replace_start.cold+0xf9/0x140 [btrfs]
  [ 1892.074346] CPU: 2 PID: 2244 Comm: btrfs Not tainted 5.5.0-rc7-default+ #942
  [ 1892.079956] RIP: 0010:btrfs_dev_replace_start.cold+0xf9/0x140 [btrfs]

  [ 1892.096576] RSP: 0018:ffffbb58c7b3fd10 EFLAGS: 00010286
  [ 1892.098311] RAX: 00000000ffffffe4 RBX: 0000000000000001 RCX: 8888888888888889
  [ 1892.100342] RDX: 0000000000000001 RSI: ffff9e889645f5d8 RDI: ffffffff92821080
  [ 1892.102291] RBP: ffff9e889645c000 R08: 000001b8878fe1f6 R09: 0000000000000000
  [ 1892.104239] R10: ffffbb58c7b3fd08 R11: 0000000000000000 R12: ffff9e88a0017000
  [ 1892.106434] R13: ffff9e889645f608 R14: ffff9e88794e1000 R15: ffff9e88a07b5200
  [ 1892.108642] FS:  00007fcaed3f18c0(0000) GS:ffff9e88bda00000(0000) knlGS:0000000000000000
  [ 1892.111558] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [ 1892.113492] CR2: 00007f52509ff420 CR3: 00000000603dd002 CR4: 0000000000160ee0

  [ 1892.115814] Call Trace:
  [ 1892.116896]  btrfs_dev_replace_by_ioctl+0x35/0x60 [btrfs]
  [ 1892.118962]  btrfs_ioctl+0x1d62/0x2550 [btrfs]

caused by the previous patch ("btrfs: scrub: Require mandatory block
group RO for dev-replace"). Hitting ENOSPC is possible and could happen
when the block group is set read-only, preventing NOCOW writes to the
area that's being accessed by dev-replace.

This has happend with scratch devices of size 12G but not with 5G and
20G, so this is depends on timing and other activity on the filesystem.
The whole replace operation is restartable, the space state should be
examined by the user in any case.

The error code is propagated back to the ioctl caller so the kernel
warning is causing false alerts.

Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-25 12:49:12 +01:00
Qu Wenruo
1bbb97b8ce btrfs: scrub: Require mandatory block group RO for dev-replace
[BUG]
For dev-replace test cases with fsstress, like btrfs/06[45] btrfs/071,
looped runs can lead to random failure, where scrub finds csum error.

The possibility is not high, around 1/20 to 1/100, but it's causing data
corruption.

The bug is observable after commit b12de52896 ("btrfs: scrub: Don't
check free space before marking a block group RO")

[CAUSE]
Dev-replace has two source of writes:

- Write duplication
  All writes to source device will also be duplicated to target device.

  Content:	Not yet persisted data/meta

- Scrub copy
  Dev-replace reused scrub code to iterate through existing extents, and
  copy the verified data to target device.

  Content:	Previously persisted data and metadata

The difference in contents makes the following race possible:
	Regular Writer		|	Dev-replace
-----------------------------------------------------------------
  ^                             |
  | Preallocate one data extent |
  | at bytenr X, len 1M		|
  v				|
  ^ Commit transaction		|
  | Now extent [X, X+1M) is in  |
  v commit root			|
 ================== Dev replace starts =========================
  				| ^
				| | Scrub extent [X, X+1M)
				| | Read [X, X+1M)
				| | (The content are mostly garbage
				| |  since it's preallocated)
  ^				| v
  | Write back happens for	|
  | extent [X, X+512K)		|
  | New data writes to both	|
  | source and target dev.	|
  v				|
				| ^
				| | Scrub writes back extent [X, X+1M)
				| | to target device.
				| | This will over write the new data in
				| | [X, X+512K)
				| v

This race can only happen for nocow writes. Thus metadata and data cow
writes are safe, as COW will never overwrite extents of previous
transaction (in commit root).

This behavior can be confirmed by disabling all fallocate related calls
in fsstress (*), then all related tests can pass a 2000 run loop.

*: FSSTRESS_AVOID="-f fallocate=0 -f allocsp=0 -f zero=0 -f insert=0 \
		   -f collapse=0 -f punch=0 -f resvsp=0"
   I didn't expect resvsp ioctl will fallback to fallocate in VFS...

[FIX]
Make dev-replace to require mandatory block group RO, and wait for current
nocow writes before calling scrub_chunk().

This patch will mostly revert commit 76a8efa171 ("btrfs: Continue replace
when set_block_ro failed") for dev-replace path.

The side effect is, dev-replace can be more strict on avaialble space, but
definitely worth to avoid data corruption.

Reported-by: Filipe Manana <fdmanana@suse.com>
Fixes: 76a8efa171 ("btrfs: Continue replace when set_block_ro failed")
Fixes: b12de52896 ("btrfs: scrub: Don't check free space before marking a block group RO")
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-24 14:35:56 +01:00
Filipe Manana
831d2fa25a Btrfs: make deduplication with range including the last block work
Since btrfs was migrated to use the generic VFS helpers for clone and
deduplication, it stopped allowing for the last block of a file to be
deduplicated when the source file size is not sector size aligned (when
eof is somewhere in the middle of the last block). There are two reasons
for that:

1) The generic code always rounds down, to a multiple of the block size,
   the range's length for deduplications. This means we end up never
   deduplicating the last block when the eof is not block size aligned,
   even for the safe case where the destination range's end offset matches
   the destination file's size. That rounding down operation is done at
   generic_remap_check_len();

2) Because of that, the btrfs specific code does not expect anymore any
   non-aligned range length's for deduplication and therefore does not
   work if such nona-aligned length is given.

This patch addresses that second part, and it depends on a patch that
fixes generic_remap_check_len(), in the VFS, which was submitted ealier
and has the following subject:

  "fs: allow deduplication of eof block into the end of the destination file"

These two patches address reports from users that started seeing lower
deduplication rates due to the last block never being deduplicated when
the file size is not aligned to the filesystem's block size.

Link: https://lore.kernel.org/linux-btrfs/2019-1576167349.500456@svIo.N5dq.dFFD/
CC: stable@vger.kernel.org # 5.1+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-23 18:24:07 +01:00
Josef Bacik
4e19443da1 btrfs: free block groups after free'ing fs trees
Sometimes when running generic/475 we would trip the
WARN_ON(cache->reserved) check when free'ing the block groups on umount.
This is because sometimes we don't commit the transaction because of IO
errors and thus do not cleanup the tree logs until at umount time.

These blocks are still reserved until they are cleaned up, but they
aren't cleaned up until _after_ we do the free block groups work.  Fix
this by moving the free after free'ing the fs roots, that way all of the
tree logs are cleaned up and we have a properly cleaned fs.  A bunch of
loops of generic/475 confirmed this fixes the problem.

CC: stable@vger.kernel.org # 4.9+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-23 17:24:39 +01:00
Nikolay Borisov
1362089d2a btrfs: Fix split-brain handling when changing FSID to metadata uuid
Current code doesn't correctly handle the situation which arises when
a file system that has METADATA_UUID_INCOMPAT flag set and has its FSID
changed to the one in metadata uuid. This causes the incompat flag to
disappear.

In case of a power failure we could end up in a situation where part of
the disks in a multi-disk filesystem are correctly reverted to
METADATA_UUID_INCOMPAT flag unset state, while others have
METADATA_UUID_INCOMPAT set and CHANGING_FSID_V2_IN_PROGRESS.

This patch corrects the behavior required to handle the case where a
disk of the second type is scanned first, creating the necessary
btrfs_fs_devices. Subsequently, when a disk which has already completed
the transition is scanned it should overwrite the data in
btrfs_fs_devices.

Reported-by: Su Yue <Damenly_Su@gmx.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-23 17:24:39 +01:00
Nikolay Borisov
0584071014 btrfs: Handle another split brain scenario with metadata uuid feature
There is one more cases which isn't handled by the original metadata
uuid work. Namely, when a filesystem has METADATA_UUID incompat bit and
the user decides to change the FSID to the original one e.g. have
metadata_uuid and fsid match. In case of power failure while this
operation is in progress we could end up in a situation where some of
the disks have the incompat bit removed and the other half have both
METADATA_UUID_INCOMPAT and FSID_CHANGING_IN_PROGRESS flags.

This patch handles the case where a disk that has successfully changed
its FSID such that it equals METADATA_UUID is scanned first.
Subsequently when a disk with both
METADATA_UUID_INCOMPAT/FSID_CHANGING_IN_PROGRESS flags is scanned
find_fsid_changed won't be able to find an appropriate btrfs_fs_devices.
This is done by extending find_fsid_changed to correctly find
btrfs_fs_devices whose metadata_uuid/fsid are the same and they match
the metadata_uuid of the currently scanned device.

Fixes: cc5de4e702 ("btrfs: Handle final split-brain possibility during fsid change")
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reported-by: Su Yue <Damenly_Su@gmx.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-23 17:24:38 +01:00
Su Yue
c6730a0e57 btrfs: Factor out metadata_uuid code from find_fsid.
find_fsid became rather hairy with the introduction of metadata uuid
changing feature. Alleviate this by factoring out the metadata uuid
specific code in a dedicated function which deals with finding
correct fsid for a device with changed uuid.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Su Yue <Damenly_Su@gmx.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-23 17:24:38 +01:00
Su Yue
c0d81c7cb2 btrfs: Call find_fsid from find_fsid_inprogress
Since find_fsid_inprogress should also handle the case in which an fs
didn't change its FSID make it call find_fsid directly. This makes the
code in device_list_add simpler by eliminating a conditional call of
find_fsid. No functional changes.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Su Yue <Damenly_Su@gmx.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-23 17:24:37 +01:00
Filipe Manana
b5e4ff9d46 Btrfs: fix infinite loop during fsync after rename operations
Recently fsstress (from fstests) sporadically started to trigger an
infinite loop during fsync operations. This turned out to be because
support for the rename exchange and whiteout operations was added to
fsstress in fstests. These operations, unlike any others in fsstress,
cause file names to be reused, whence triggering this issue. However
it's not necessary to use rename exchange and rename whiteout operations
trigger this issue, simple rename operations and file creations are
enough to trigger the issue.

The issue boils down to when we are logging inodes that conflict (that
had the name of any inode we need to log during the fsync operation), we
keep logging them even if they were already logged before, and after
that we check if there's any other inode that conflicts with them and
then add it again to the list of inodes to log. Skipping already logged
inodes fixes the issue.

Consider the following example:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt

  $ mkdir /mnt/testdir                           # inode 257

  $ touch /mnt/testdir/zz                        # inode 258
  $ ln /mnt/testdir/zz /mnt/testdir/zz_link

  $ touch /mnt/testdir/a                         # inode 259

  $ sync

  # The following 3 renames achieve the same result as a rename exchange
  # operation (<rename_exchange> /mnt/testdir/zz_link to /mnt/testdir/a).

  $ mv /mnt/testdir/a /mnt/testdir/a/tmp
  $ mv /mnt/testdir/zz_link /mnt/testdir/a
  $ mv /mnt/testdir/a/tmp /mnt/testdir/zz_link

  # The following rename and file creation give the same result as a
  # rename whiteout operation (<rename_whiteout> zz to a2).

  $ mv /mnt/testdir/zz /mnt/testdir/a2
  $ touch /mnt/testdir/zz                        # inode 260

  $ xfs_io -c fsync /mnt/testdir/zz
    --> results in the infinite loop

The following steps happen:

1) When logging inode 260, we find that its reference named "zz" was
   used by inode 258 in the previous transaction (through the commit
   root), so inode 258 is added to the list of conflicting indoes that
   need to be logged;

2) After logging inode 258, we find that its reference named "a" was
   used by inode 259 in the previous transaction, and therefore we add
   inode 259 to the list of conflicting inodes to be logged;

3) After logging inode 259, we find that its reference named "zz_link"
   was used by inode 258 in the previous transaction - we add inode 258
   to the list of conflicting inodes to log, again - we had already
   logged it before at step 3. After logging it again, we find again
   that inode 259 conflicts with him, and we add again 259 to the list,
   etc - we end up repeating all the previous steps.

So fix this by skipping logging of conflicting inodes that were already
logged.

Fixes: 6b5fc433a7 ("Btrfs: fix fsync after succession of renames of different files")
CC: stable@vger.kernel.org # 5.1+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-23 17:24:37 +01:00
Josef Bacik
d62b23c949 btrfs: set trans->drity in btrfs_commit_transaction
If we abort a transaction we have the following sequence

if (!trans->dirty && list_empty(&trans->new_bgs))
	return;
WRITE_ONCE(trans->transaction->aborted, err);

The idea being if we didn't modify anything with our trans handle then
we don't really need to abort the whole transaction, maybe the other
trans handles are fine and we can carry on.

However in the case of create_snapshot we add a pending_snapshot object
to our transaction and then commit the transaction.  We don't actually
modify anything.  sync() behaves the same way, attach to an existing
transaction and commit it.  This means that if we have an IO error in
the right places we could abort the committing transaction with our
trans->dirty being not set and thus not set transaction->aborted.

This is a problem because in the create_snapshot() case we depend on
pending->error being set to something, or btrfs_commit_transaction
returning an error.

If we are not the trans handle that gets to commit the transaction, and
we're waiting on the commit to happen we get our return value from
cur_trans->aborted.  If this was not set to anything because sync() hit
an error in the transaction commit before it could modify anything then
cur_trans->aborted would be 0.  Thus we'd return 0 from
btrfs_commit_transaction() in create_snapshot.

This is a problem because we then try to do things with
pending_snapshot->snap, which will be NULL because we didn't create the
snapshot, and then we'll get a NULL pointer dereference like the
following

"BUG: kernel NULL pointer dereference, address: 00000000000001f0"
RIP: 0010:btrfs_orphan_cleanup+0x2d/0x330
Call Trace:
 ? btrfs_mksubvol.isra.31+0x3f2/0x510
 btrfs_mksubvol.isra.31+0x4bc/0x510
 ? __sb_start_write+0xfa/0x200
 ? mnt_want_write_file+0x24/0x50
 btrfs_ioctl_snap_create_transid+0x16c/0x1a0
 btrfs_ioctl_snap_create_v2+0x11e/0x1a0
 btrfs_ioctl+0x1534/0x2c10
 ? free_debug_processing+0x262/0x2a3
 do_vfs_ioctl+0xa6/0x6b0
 ? do_sys_open+0x188/0x220
 ? syscall_trace_enter+0x1f8/0x330
 ksys_ioctl+0x60/0x90
 __x64_sys_ioctl+0x16/0x20
 do_syscall_64+0x4a/0x1b0

In order to fix this we need to make sure anybody who calls
commit_transaction has trans->dirty set so that they properly set the
trans->transaction->aborted value properly so any waiters know bad
things happened.

This was found while I was running generic/475 with my modified
fsstress, it reproduced within a few runs.  I ran with this patch all
night and didn't see the problem again.

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-23 17:24:37 +01:00
Josef Bacik
889bfa3908 btrfs: drop log root for dropped roots
If we fsync on a subvolume and create a log root for that volume, and
then later delete that subvolume we'll never clean up its log root.  Fix
this by making switch_commit_roots free the log for any dropped roots we
encounter.  The extra churn is because we need a btrfs_trans_handle, not
the btrfs_transaction.

CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-23 17:24:36 +01:00
Anand Jain
668e48af7a btrfs: sysfs, add devid/dev_state kobject and device attributes
New sysfs attributes that track the filesystem status of devices, stored
in the per-filesystem directory in /sys/fs/btrfs/FSID/devinfo . There's
a directory for each device, with name corresponding to the numerical
device id.

  in_fs_metadata    - device is in the list of fs metadata
  missing           - device is missing (no device node or block device)
  replace_target    - device is target of replace
  writeable         - writes from fs are allowed

These attributes reflect the state of the device::dev_state and created
at mount time.

Sample output:
  $ pwd
   /sys/fs/btrfs/6e1961f1-5918-4ecc-a22f-948897b409f7/devinfo/1/
  $ ls
    in_fs_metadata  missing  replace_target  writeable
  $ cat missing
    0

The output from these attributes are 0 or 1. 0 indicates unset and 1
indicates set.  These attributes are readonly.

It is observed that the device delete thread and sysfs read thread will
not race because the delete thread calls sysfs kobject_put() which in
turn waits for existing sysfs read to complete.

Note for device replace devid swap:

During the replace the target device temporarily assumes devid 0 before
assigning the devid of the soruce device.

In btrfs_dev_replace_finishing() we remove source sysfs devid using the
function btrfs_sysfs_remove_devices_attr(), so after that call
kobject_rename() to update the devid in the sysfs.  This adds and calls
btrfs_sysfs_update_devid() helper function to update the device id.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-23 17:24:36 +01:00
Nikolay Borisov
1776ad172e btrfs: Refactor btrfs_rmap_block to improve readability
Move variables to appropriate scope. Remove last BUG_ON in the function
and rework error handling accordingly. Make the duplicate detection code
more straightforward. Use in_range macro. And give variables more
descriptive name by explicitly distinguishing between IO stripe size
(size recorded in the chunk item) and data stripe size (the size of
an actual stripe, constituting a logical chunk/block group).

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-23 17:24:35 +01:00
Nikolay Borisov
bf2e2eb060 btrfs: Add self-tests for btrfs_rmap_block
Add RAID1 and single testcases to verify that data stripes are excluded
from super block locations and that the address mapping is valid.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-23 17:24:35 +01:00
Nikolay Borisov
b3ad2c17fd btrfs: selftests: Add support for dummy devices
Add basic infrastructure to create and link dummy btrfs_devices. This
will be used in the pending btrfs_rmap_block test which deals with
the block groups.

Calling btrfs_alloc_dummy_device will link the newly created device to
the passed fs_info and the test framework will free them once the test
is finished.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-23 17:24:34 +01:00
Nikolay Borisov
96a14336bd btrfs: Move and unexport btrfs_rmap_block
It's used only during initial block group reading to map physical
address of super block to a list of logical ones. Make it private to
block-group.c, add proper kernel doc and ensure it's exported only for
tests.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-23 17:24:34 +01:00
David Sterba
68c467cbb2 btrfs: separate definition of assertion failure handlers
There's a report where objtool detects unreachable instructions, eg.:

  fs/btrfs/ctree.o: warning: objtool: btrfs_search_slot()+0x2d4: unreachable instruction

This seems to be a false positive due to compiler version. The cause is
in the ASSERT macro implementation that does the conditional check as
IS_DEFINED(CONFIG_BTRFS_ASSERT) and not an #ifdef.

To avoid that, use the ifdefs directly.

There are still 2 reports that aren't fixed:

  fs/btrfs/extent_io.o: warning: objtool: __set_extent_bit()+0x71f: unreachable instruction
  fs/btrfs/relocation.o: warning: objtool: find_data_references()+0x4e0: unreachable instruction

Co-developed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-23 17:24:23 +01:00
Anand Jain
a69976bc69 btrfs: device stats, log when stats are zeroed
We had a report indicating that some read errors aren't reported by the
device stats in the userland. It is important to have the errors
reported in the device stat as user land scripts might depend on it to
take the reasonable corrective actions. But to debug these issue we need
to be really sure that request to reset the device stat did not come
from the userland itself. So log an info message when device error reset
happens.

For example:
 BTRFS info (device sdc): device stats zeroed by btrfs(9223)

Reported-by: philip@philip-seeger.de
Link: https://www.spinics.net/lists/linux-btrfs/msg96528.html
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:41:02 +01:00
Josef Bacik
556755a8a9 btrfs: fix improper setting of scanned for range cyclic write cache pages
We noticed that we were having regular CG OOM kills in cases where there
was still enough dirty pages to avoid OOM'ing.  It turned out there's
this corner case in btrfs's handling of range_cyclic where files that
were being redirtied were not getting fully written out because of how
we do range_cyclic writeback.

We unconditionally were setting scanned = 1; the first time we found any
pages in the inode.  This isn't actually what we want, we want it to be
set if we've scanned the entire file.  For range_cyclic we could be
starting in the middle or towards the end of the file, so we could write
one page and then not write any of the other dirty pages in the file
because we set scanned = 1.

Fix this by not setting scanned = 1 if we find pages.  The rules for
setting scanned should be

1) !range_cyclic.  In this case we have a specified range to write out.
2) range_cyclic && index == 0.  In this case we've started at the
   beginning and there is no need to loop around a second time.
3) range_cyclic && we started at index > 0 and we've reached the end of
   the file without satisfying our nr_to_write.

This patch fixes both of our writepages implementations to make sure
these rules hold true.  This fixed our over zealous CG OOMs in
production.

Fixes: d1310b2e0c ("Btrfs: Split the extent_map code into two parts")
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add comment ]
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:41:02 +01:00
David Sterba
4babad1019 btrfs: safely advance counter when looking up bio csums
Dan's smatch tool reports

  fs/btrfs/file-item.c:295 btrfs_lookup_bio_sums()
  warn: should this be 'count == -1'

which points to the while (count--) loop. With count == 0 the check
itself could decrement it to -1. There's a WARN_ON a few lines below
that has never been seen in practice though.

It turns out that the value of page_bytes_left matches the count (by
sectorsize multiples). The loop never reaches the state where count
would go to -1, because page_bytes_left == 0 is found first and this
breaks out.

For clarity, use only plain check on count (and only for positive
value), decrement safely inside the loop. Any other discrepancy after
the whole bio list processing should be reported by the exising
WARN_ON_ONCE as well.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:41:01 +01:00
David Sterba
94f8c46566 btrfs: remove unused member btrfs_device::work
This is a leftover from recently removed bio scheduling framework.

Fixes: ba8a9d0795 ("Btrfs: delete the entire async bio submission framework")
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:41:01 +01:00
Johannes Thumshirn
ef0a82da81 btrfs: remove unnecessary wrapper get_alloc_profile
btrfs_get_alloc_profile() is a simple wrapper over get_alloc_profile().
The only difference is btrfs_get_alloc_profile() is visible to other
functions in btrfs while get_alloc_profile() is static and thus only
visible to functions in block-group.c.

Let's just fold get_alloc_profile() into btrfs_get_alloc_profile() to
get rid of the unnecessary second function.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Johannes Thumshirn <jth@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:41:01 +01:00
Dennis Zhou
81b29a3bf7 btrfs: add correction to handle -1 edge case in async discard
From Dave's testing described below, it's possible to drive a file
system to have bogus values of discardable_extents and _bytes.  As
btrfs_discard_calc_delay() is the only user of discardable_extents, we
can correct here for any negative discardable_extents/discardable_bytes.

The problem is not reliably reproducible. The workload that created it
was based on linux git tree, switching between release tags, then
everytihng deleted followed by a full rebalance. At this state the
values of discardable_bytes was 16K and discardable_extents was -1,
expected values 0 and 0.

Repeating the workload again did not correct the bogus values so the
offset seems to be stable once it happens.

Reported-by: David Sterba <dsterba@suse.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:41:01 +01:00
Dennis Zhou
27f0afc737 btrfs: ensure removal of discardable_* in free_bitmap()
Most callers of free_bitmap() only call it if bitmap_info->bytes is 0.
However, there are certain cases where we may free the free space cache
via __btrfs_remove_free_space_cache(). This exposes a path where
free_bitmap() is called regardless. This may result in a bad accounting
situation for discardable_bytes and discardable_extents. So, remove the
stats and call btrfs_discard_update_discardable().

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:41:01 +01:00
Dennis Zhou
f9bb615af2 btrfs: make smaller extents more likely to go into bitmaps
It's less than ideal for small extents to eat into our extent budget, so
force extents <= 32KB into the bitmaps save for the first handful.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:41:00 +01:00
Dennis Zhou
5d90c5c757 btrfs: increase the metadata allowance for the free_space_cache
Currently, there is no way for the free space cache to recover from
being serviced by purely bitmaps because the extent threshold is set to
0 in recalculate_thresholds() when we surpass the metadata allowance.

This adds a recovery mechanism by keeping large extents out of the
bitmaps and increases the metadata upper bound to 64KB. The recovery
mechanism bypasses this upper bound, thus making it a soft upper bound.
But, with the bypass being 1MB or greater, it shouldn't add unbounded
overhead.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:41:00 +01:00
Dennis Zhou
dbc2a8c927 btrfs: add async discard implementation overview
Give a brief overview for how async discard is implemented.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:41:00 +01:00
Dennis Zhou
9ddf648f9c btrfs: keep track of discard reuse stats
Keep track of how much we are discarding and how often we are reusing
with async discard. The discard_*_bytes values don't need any special
protection because the work item provides the single threaded access.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:41:00 +01:00
Dennis Zhou
5cb0724e1b btrfs: only keep track of data extents for async discard
As mentioned earlier, discarding data can be done either by issuing an
explicit discard or implicitly by reusing the LBA. Metadata block_groups
see much more frequent reuse due to well it being metadata. So instead
of explicitly discarding metadata block_groups, just leave them be and
let the latter implicit discarding be done for them.

For mixed block_groups, block_groups which contain both metadata and
data, we let them be as higher fragmentation is expected.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:41:00 +01:00
Dennis Zhou
7fe6d45e40 btrfs: have multiple discard lists
Non-block group destruction discarding currently only had a single list
with no minimum discard length. This can lead to caravaning more
meaningful discards behind a heavily fragmented block group.

This adds support for multiple lists with minimum discard lengths to
prevent the caravan effect. We promote block groups back up when we
exceed the BTRFS_ASYNC_DISCARD_MAX_FILTER size, currently we support
only 2 lists with filters of 1MB and 32KB respectively.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:41:00 +01:00
Dennis Zhou
19b2a2c719 btrfs: make max async discard size tunable
Expose max_discard_size as a tunable via sysfs and switch the current
fixed maximum to the default value.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:59 +01:00
Dennis Zhou
4aa9ad5203 btrfs: limit max discard size for async discard
Throttle the maximum size of a discard so that we can provide an upper
bound for the rate of async discard. While the block layer is able to
split discards into the appropriate sized discards, we want to be able
to account more accurately the rate at which we are consuming NCQ slots
as well as limit the upper bound of work for a discard.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:59 +01:00
Dennis Zhou
e93591bb6e btrfs: add kbps discard rate limit for async discard
Provide the ability to rate limit based on kbps in addition to iops as
additional guides for the target discard rate. The delay used ends up
being max(kbps_delay, iops_delay).

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:59 +01:00
Dennis Zhou
a230930084 btrfs: calculate discard delay based on number of extents
An earlier patch keeps track of discardable_extents. These are
undiscarded extents managed by the free space cache. Here, we will use
this to dynamically calculate the discard delay interval.

There are 3 rate to consider. The first is the target convergence rate,
the rate to discard all discardable_extents over the
BTRFS_DISCARD_TARGET_MSEC time frame. This is clamped by the lower
limit, the iops limit or BTRFS_DISCARD_MIN_DELAY (1ms), and the upper
limit, BTRFS_DISCARD_MAX_DELAY (1s). We reevaluate this delay every
transaction commit.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:59 +01:00
Dennis Zhou
5dc7c10b87 btrfs: keep track of discardable_bytes for async discard
Keep track of this metric so that we can understand how ahead or behind
we are in discarding rate. This uses the same accounting method as
discardable_extents, deltas between previous/current values and
propagating them up.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:59 +01:00
Dennis Zhou
dfb79ddb13 btrfs: track discardable extents for async discard
The number of discardable extents will serve as the rate limiting metric
for how often we should discard. This keeps track of discardable extents
in the free space caches by maintaining deltas and propagating them to
the global count.

The deltas are calculated from 2 values stored in PREV and CURR entries,
then propagated up to the global discard ctl.  The current counter value
becomes the previous counter value after update.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:58 +01:00
Dennis Zhou
e4faab844a btrfs: sysfs: add UUID/debug/discard directory
Setup base sysfs directory for discard stats + tunables.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:58 +01:00
Dennis Zhou
93945cb43e btrfs: sysfs: make UUID/debug have its own kobject
Btrfs only allowed attributes to be exposed in debug/. Let's let other
groups be created by making debug its own kobject.

This also makes the per-fs debug options separate from the global
features mount attributes. This seems to be needed as
sysfs_create_files() requires const struct attribute * while
sysfs_create_group() can take struct attribute *. This seems nicer as
per file system, you'll probably use to_fs_info().

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:58 +01:00
Dennis Zhou
71e8978eb4 btrfs: sysfs: add removal calls for debug/
We probably should call sysfs_remove_group() on debug/.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:58 +01:00
Dennis Zhou
2bee7eb8bb btrfs: discard one region at a time in async discard
The prior two patches added discarding via a background workqueue. This
just piggybacked off of the fstrim code to trim the whole block at once.
Well inevitably this is worse performance wise and will aggressively
overtrim. But it was nice to plumb the other infrastructure to keep the
patches easier to review.

This adds the real goal of this series which is discarding slowly (ie. a
slow long running fstrim). The discarding is split into two phases,
extents and then bitmaps. The reason for this is two fold. First, the
bitmap regions overlap the extent regions. Second, discarding the
extents first will let the newly trimmed bitmaps have the highest chance
of coalescing when being readded to the free space cache.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:58 +01:00
Dennis Zhou
6e80d4f8c4 btrfs: handle empty block_group removal for async discard
block_group removal is a little tricky. It can race with the extent
allocator, the cleaner thread, and balancing. The current path is for a
block_group to be added to the unused_bgs list. Then, when the cleaner
thread comes around, it starts a transaction and then proceeds with
removing the block_group. Extents that are pinned are subsequently
removed from the pinned trees and then eventually a discard is issued
for the entire block_group.

Async discard introduces another player into the game, the discard
workqueue. While it has none of the racing issues, the new problem is
ensuring we don't leave free space untrimmed prior to forgetting the
block_group.  This is handled by placing fully free block_groups on a
separate discard queue. This is necessary to maintain discarding order
as in the future we will slowly trim even fully free block_groups. The
ordering helps us make progress on the same block_group rather than say
the last fully freed block_group or needing to search through the fully
freed block groups at the beginning of a list and insert after.

The new order of events is a fully freed block group gets placed on the
unused discard queue first. Once it's processed, it will be placed on
the unusued_bgs list and then the original sequence of events will
happen, just without the final whole block_group discard.

The mount flags can change when processing unused_bgs, so when flipping
from DISCARD to DISCARD_ASYNC, the unused_bgs must be punted to the
discard_list to be trimmed. If we flip off DISCARD_ASYNC, we punt
free block groups on the discard_list to the unused_bg queue which will
do the final discard for us.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:57 +01:00
Dennis Zhou
b0643e59cf btrfs: add the beginning of async discard, discard workqueue
When discard is enabled, everytime a pinned extent is released back to
the block_group's free space cache, a discard is issued for the extent.
This is an overeager approach when it comes to discarding and helping
the SSD maintain enough free space to prevent severe garbage collection
situations.

This adds the beginning of async discard. Instead of issuing a discard
prior to returning it to the free space, it is just marked as untrimmed.
The block_group is then added to a LRU which then feeds into a workqueue
to issue discards at a much slower rate. Full discarding of unused block
groups is still done and will be addressed in a future patch of the
series.

For now, we don't persist the discard state of extents and bitmaps.
Therefore, our failure recovery mode will be to consider extents
untrimmed. This lets us handle failure and unmounting as one in the
same.

On a number of Facebook webservers, I collected data every minute
accounting the time we spent in btrfs_finish_extent_commit() (col. 1)
and in btrfs_commit_transaction() (col. 2). btrfs_finish_extent_commit()
is where we discard extents synchronously before returning them to the
free space cache.

discard=sync:
                 p99 total per minute       p99 total per minute
      Drive   |   extent_commit() (ms)  |    commit_trans() (ms)
    ---------------------------------------------------------------
     Drive A  |           434           |          1170
     Drive B  |           880           |          2330
     Drive C  |          2943           |          3920
     Drive D  |          4763           |          5701

discard=async:
                 p99 total per minute       p99 total per minute
      Drive   |   extent_commit() (ms)  |    commit_trans() (ms)
    --------------------------------------------------------------
     Drive A  |           134           |           956
     Drive B  |            64           |          1972
     Drive C  |            59           |          1032
     Drive D  |            62           |          1200

While it's not great that the stats are cumulative over 1m, all of these
servers are running the same workload and and the delta between the two
are substantial. We are spending significantly less time in
btrfs_finish_extent_commit() which is responsible for discarding.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:57 +01:00
Dennis Zhou
da080fe1ba btrfs: keep track of free space bitmap trim status cleanliness
There is a cap in btrfs in the amount of free extents that a block group
can have. When it surpasses that threshold, future extents are placed
into bitmaps. Instead of keeping track of if a certain bit is trimmed or
not in a second bitmap, keep track of the relative state of the bitmap.

With async discard, trimming bitmaps becomes a more frequent operation.
As a trade off with simplicity, we keep track of if discarding a bitmap
is in progress. If we fully scan a bitmap and trim as necessary, the
bitmap is marked clean. This has some caveats as the min block size may
skip over regions deemed too small. But this should be a reasonable
trade off rather than keeping a second bitmap and making allocation
paths more complex. The downside is we may overtrim, but ideally the min
block size should prevent us from doing that too often and getting stuck
trimming pathological cases.

BTRFS_TRIM_STATE_TRIMMING is added to indicate a bitmap is in the
process of being trimmed. If additional free space is added to that
bitmap, the bit is cleared. A bitmap will be marked
BTRFS_TRIM_STATE_TRIMMED if the trimming code was able to reach the end
of it and the former is still set.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:57 +01:00
Dennis Zhou
a7ccb25585 btrfs: keep track of which extents have been discarded
Async discard will use the free space cache as backing knowledge for
which extents to discard. This patch plumbs knowledge about which
extents need to be discarded into the free space cache from
unpin_extent_range().

An untrimmed extent can merge with everything as this is a new region.
Absorbing trimmed extents is a tradeoff to for greater coalescing which
makes life better for find_free_extent(). Additionally, it seems the
size of a trim isn't as problematic as the trim io itself.

When reading in the free space cache from disk, if sync is set, mark all
extents as trimmed. The current code ensures at transaction commit that
all free space is trimmed when sync is set, so this reflects that.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:57 +01:00
Dennis Zhou
46b27f5059 btrfs: rename DISCARD mount option to to DISCARD_SYNC
This series introduces async discard which will use the flag
DISCARD_ASYNC, so rename the original flag to DISCARD_SYNC as it is
synchronously done in transaction commit.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:57 +01:00
Qu Wenruo
147a097cf0 btrfs: tree-checker: Verify location key for DIR_ITEM/DIR_INDEX
[PROBLEM]
There is a user report in the mail list, showing the following corrupted
tree blocks:

       item 62 key (486836 DIR_ITEM 2543451757) itemoff 6273 itemsize 74
               location key (4065004 INODE_ITEM 1073741824) type FILE
               transid 21397 data_len 0 name_len 44
               name: FILENAME

Note that location key, its offset should be 0 for all INODE_ITEMS.
This caused failed lookup of the inode.

[CAUSE]
That offending value, 1073741824, is 0x40000000. So this looks like a
memory bit flip.

[FIX]
This patch will enhance tree-checker to check location key of
DIR_INDEX/DIR_ITEM/XATTR_ITEM.

There are several different combinations needs to check:

- item_key.type == DIR_INDEX/DIR_ITEM

  * location_key.type == BTRFS_INODE_ITEM_KEY
    This location_key should follow the check in inode_item check.
  * location_key.type == BTRFS_ROOT_ITEM_KEY
    Despite the existing check, DIR_INDEX/DIR_ITEM can only points to
    subvolume trees.
  * All other keys are not allowed.

- item_key.type == XATTR_ITEM
  location_key should be all 0.

Reported-by: Mike Gilbert <floppymaster@gmail.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:56 +01:00
Qu Wenruo
57a0e67491 btrfs: tree-checker: Refactor root key check into separate function
ROOT_ITEM key check itself is not as simple as single line check, and
will be reused for both ROOT_ITEM and DIR_ITEM/DIR_INDEX location key
check, so refactor such check into check_root_key().

Also since we are here, fix a comment error about ROOT_ITEM offset,
which is transid of snapshot creation, not some "older kernel behavior".

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:56 +01:00
Qu Wenruo
c23c77b097 btrfs: tree-checker: Refactor inode key check into seperate function
Inode key check is not as easy as several lines, and it will be called
in more than one location (INODE_ITEM check and
DIR_ITEM/DIR_INDEX/XATTR_ITEM location key check).

So here refactor such check into check_inode_key().  And add extra
checks for XATTR_ITEM.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:56 +01:00
Qu Wenruo
c3053ebb0b btrfs: tree-checker: Clean up fs_info parameter from error message wrapper
The @fs_info parameter can be extracted from extent_buffer structure,
and there are already some wrappers getting rid of the @fs_info
parameter.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:56 +01:00
Qu Wenruo
f6d2a5c263 btrfs: tree-checker: Check leaf chunk item size
Inspired by btrfs-progs github issue #208, where chunk item in chunk
tree has invalid num_stripes (0).

Although that can already be caught by current btrfs_check_chunk_valid(),
that function doesn't really check item size as it needs to handle chunk
item in super block sys_chunk_array().

This patch will add two extra checks for chunk items in chunk tree:

- Basic chunk item size
  If the item is smaller than btrfs_chunk (which already contains one
  stripe), exit right now as reading num_stripes may even go beyond
  eb boundary.

- Item size check against num_stripes
  If item size doesn't match with calculated chunk size, then either the
  item size or the num_stripes is corrupted. Error out anyway.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:56 +01:00
zhengbin
0ab575c5df btrfs: Remove unneeded semicolon
Fixes coccicheck warning:

fs/btrfs/print-tree.c:320:3-4: Unneeded semicolon

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:55 +01:00
Omar Sandoval
95690e58e1 btrfs: remove struct find_free_extent.ram_bytes
This hasn't been used since it was first introduced in commit
b4bd745d12 ("btrfs: Introduce find_free_extent_ctl structure for later
rework"). Passing that to btrfs_add_reserved_bytes in find_free_extent
is not strictly necessary and using the local ram_bytes instead seems
cleaner.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:55 +01:00
Omar Sandoval
c8b04030c5 btrfs: simplify compressed/inline check in __extent_writepage_io()
Commit 7087a9d8db ("btrfs: Remove
extent_io_ops::writepage_end_io_hook") left this logic in a confusing
state. Simplify it.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:55 +01:00
Omar Sandoval
39b07b5d70 btrfs: drop create parameter to btrfs_get_extent()
We only pass this as 1 from __extent_writepage_io(). The parameter
basically means "pretend I didn't pass in a page". This is silly since
we can simply not pass in the page. Get rid of the parameter from
btrfs_get_extent(), and since it's used as a get_extent_t callback,
remove it from get_extent_t and btree_get_extent(), neither of which
need it.

While we're here, let's document btrfs_get_extent().

Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:55 +01:00
Omar Sandoval
f95d713b54 btrfs: remove redundant i_size check in __extent_writepage_io()
In __extent_writepage_io(), we check whether

  i_size <= page_offset(page).

Note that if i_size < page_offset(page), then
i_size >> PAGE_SHIFT < page->index.

If i_size == page_offset(page), then
i_size >> PAGE_SHIFT == page->index && offset_in_page(i_size) == 0.

__extent_writepage() already has a check for these cases that
returns without calling __extent_writepage_io():

  end_index = i_size >> PAGE_SHIFT
  pg_offset = offset_in_page(i_size);
  if (page->index > end_index ||
     (page->index == end_index && !pg_offset)) {
          page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
          unlock_page(page);
          return 0;
  }

Get rid of the one in __extent_writepage_io(), which was obsoleted in
211c17f51f ("Fix corners in writepage and btrfs_truncate_page").

Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:55 +01:00
Omar Sandoval
169d2c875e btrfs: remove trivial goto label in __extent_writepage()
Since 40f765805f ("Btrfs: split up __extent_writepage to lower stack
usage"), done_unlocked is simply a return 0. Get rid of it.
Mid-statement block returns don seem to make the code less readable here.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:54 +01:00
Omar Sandoval
eb70d22263 btrfs: remove unnecessary pg_offset assignments in __extent_writepage()
We're initializing pg_offset to 0, setting it immediately, then
reassigning it to 0 again after. The former became unnecessary in
211c17f51f ("Fix corners in writepage and btrfs_truncate_page"). The
latter is a leftover that should've been removed in 40f765805f
("Btrfs: split up __extent_writepage to lower stack usage"). Remove
both.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:54 +01:00
Omar Sandoval
bffe633e00 btrfs: make btrfs_ordered_extent naming consistent with btrfs_file_extent_item
ordered->start, ordered->len, and ordered->disk_len correspond to
fi->disk_bytenr, fi->num_bytes, and fi->disk_num_bytes, respectively.
It's confusing to translate between the two naming schemes. Since a
btrfs_ordered_extent is basically a pending btrfs_file_extent_item,
let's make the former use the naming from the latter.

Note that I didn't touch the names in tracepoints just in case there are
scripts depending on the current naming.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:54 +01:00
Omar Sandoval
313facc5bd btrfs: remove dead snapshot-aware defrag code
Snapshot-aware defrag has been disabled since commit 8101c8dbf6
("Btrfs: disable snapshot aware defrag for now") almost 6 years ago.
Let's remove the dead code. If someone is up to the task of bringing it
back, they can dig it up from git.

This is logically a revert of commit 38c227d87c ("Btrfs:
snapshot-aware defrag") except that now we have to clear the
EXTENT_DEFRAG bit to avoid need_force_cow() returning true forever.

The reasons to disable were caused by runtime problems (like long stalls
or memory consumption) on heavily referenced extents (eg. thousands of
snapshots). There were attempts to fix that but never finished.

Current defrag breaks the extent references and some users prefer that
behaviour over the one implemented by snapshot aware (ie. keeping links
for defragmentation).  To enable both usecases we'd need to extend
defrag ioctl but let's do that properly from scratch.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ enhance ]
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:54 +01:00
Omar Sandoval
db72e47f79 btrfs: get rid of at_offset parameter to btrfs_lookup_bio_sums()
We can encode this in the offset parameter: -1 means use the page
offsets, anything else is a valid offset.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:54 +01:00
Omar Sandoval
e62958fce9 btrfs: get rid of trivial __btrfs_lookup_bio_sums() wrappers
Currently, we have two wrappers for __btrfs_lookup_bio_sums():
btrfs_lookup_bio_sums_dio(), which is used for direct I/O, and
btrfs_lookup_bio_sums(), which is used everywhere else. The only
difference is that the _dio variant looks up csums starting at the given
offset instead of using the page index, which isn't actually direct
I/O-specific. Let's clean up the signature and return value of
__btrfs_lookup_bio_sums(), rename it to btrfs_lookup_bio_sums(), and get
rid of the trivial helpers.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:53 +01:00
Johannes Thumshirn
321f69f86a btrfs: reset device back to allocation state when removing
When closing a device, btrfs_close_one_device() first allocates a new
device, copies the device to close's name, replaces it in the dev_list
with the copy and then finally frees it.

This involves two memory allocation, which can potentially fail. As this
code path is tricky to unwind, the allocation failures where handled by
BUG_ON()s.

But this copying isn't strictly needed, all that is needed is resetting
the device in question to it's state it had after the allocation.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:53 +01:00
Johannes Thumshirn
3fff3975a7 btrfs: decrement number of open devices after closing the device not before
In btrfs_close_one_device we're decrementing the number of open devices
before we're calling btrfs_close_bdev().

As there is no intermediate exit between these points in this function it
is technically OK to do so, but it makes the code a bit harder to understand.

Move both operations closer together and move the decrement step after
btrfs_close_bdev().

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:53 +01:00
Omar Sandoval
6bb6b51447 btrfs: use simple_dir_inode_operations for placeholder subvolume directory
When you snapshot a subvolume containing a subvolume, you get a
placeholder directory where the subvolume would be. These directories
have their own btrfs_dir_ro_inode_operations.

Al pointed out [1] that these directories can use simple_lookup()
instead of btrfs_lookup(), as they are always empty. Furthermore, they
can use the default generic_permission() instead of btrfs_permission();
the additional checks in the latter don't matter because we can't write
to the directory anyways. Finally, they can use the default
generic_update_time() instead of btrfs_update_time(), as the inode
doesn't exist on disk and doesn't need any special handling.

All together, this means that we can get rid of
btrfs_dir_ro_inode_operations and use simple_dir_inode_operations
instead.

1: https://lore.kernel.org/linux-btrfs/20190929052934.GY26530@ZenIV.linux.org.uk/

Cc: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add comment ]
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:53 +01:00
Johannes Thumshirn
b38f4cbd65 btrfs: remove impossible WARN_ON in btrfs_destroy_dev_replace_tgtdev()
We have a user report, that cppcheck is complaining about a possible
NULL-pointer dereference in btrfs_destroy_dev_replace_tgtdev().

We're first dereferencing the 'tgtdev' variable and the later check for
the validity of the pointer with a WARN_ON(!tgtdev);

But all callers of btrfs_destroy_dev_replace_tgtdev() either explicitly
check if 'tgtdev' is non-NULL or directly allocate 'tgtdev', so the
WARN_ON() is impossible to hit. Just remove it to silence the checker's
complains.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=205003
Signed-off-by: Johannes Thumshirn <jth@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:53 +01:00
Johannes Thumshirn
1296995225 btrfs: remove superfluous BUG_ON() in integrity checks
btrfsic_process_superblock() BUG_ON()s if 'state' is NULL. But this can
never happen as the only caller from btrfsic_process_superblock() is
btrfsic_mount() which allocates 'state' some lines above calling
btrfsic_process_superblock() and checks for the allocation to succeed.

Let's just remove the impossible to hit BUG_ON().

Signed-off-by: Johannes Thumshirn <jth@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:52 +01:00
Johannes Thumshirn
3dbd351df4 btrfs: fix possible NULL-pointer dereference in integrity checks
A user reports a possible NULL-pointer dereference in
btrfsic_process_superblock(). We are assigning state->fs_info to a local
fs_info variable and afterwards checking for the presence of state.

While we would BUG_ON() a NULL state anyways, we can also just remove
the local fs_info copy, as fs_info is only used once as the first
argument for btrfs_num_copies(). There we can just pass in
state->fs_info as well.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=205003
Signed-off-by: Johannes Thumshirn <jth@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:52 +01:00
Josef Bacik
f893556637 btrfs: kill min_allocable_bytes in inc_block_group_ro
This is a relic from a time before we had a proper reservation mechanism
and you could end up with really full chunks at chunk allocation time.
This doesn't make sense anymore, so just kill it.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:52 +01:00
Josef Bacik
9f246926b4 btrfs: don't pass system_chunk into can_overcommit
We have the space_info, we can just check its flags to see if it's the
system chunk space info.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:52 +01:00
Nikolay Borisov
511a32b549 btrfs: Opencode ordered_data_tree_panic
It's a simple wrapper over btrfs_panic and is called only once. Just
open code it.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:52 +01:00
Qu Wenruo
430640e316 btrfs: relocation: Output current relocation stage at btrfs_relocate_block_group()
There are two relocation stages but both print the same message. Add the
description of the stage. This can help debugging or provides
informative message to users.

  BTRFS info (device dm-5): balance: start -d -m -s
  BTRFS info (device dm-5): relocating block group 30408704 flags metadata|dup
  BTRFS info (device dm-5): found 2 extents, stage: move data extents
  BTRFS info (device dm-5): relocating block group 22020096 flags system|dup
  BTRFS info (device dm-5): found 1 extents, stage: move data extents
  BTRFS info (device dm-5): relocating block group 13631488 flags data
  BTRFS info (device dm-5): found 1 extents, stage: move data extents
  BTRFS info (device dm-5): found 1 extents, stage: update data pointers
  BTRFS info (device dm-5): balance: ended with status: 0

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:51 +01:00
Yunfeng Ye
76de60ed04 btrfs: remove unused condition check in btrfs_page_mkwrite()
The condition '!ret2' is always true. commit 717beb96d9 ("Btrfs: fix
regression in btrfs_page_mkwrite() from vm_fault_t conversion") left
behind the check after moving this code out of the goto, so remove the
unused condition check.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:51 +01:00
Nikolay Borisov
36ee0b44ad btrfs: Remove redundant WARN_ON in walk_down_log_tree
level <0 and level >= BTRFS_MAX_LEVEL are already performed upon
extent buffer read by tree checker in btrfs_check_node.
go. As far as 'level <= 0'  we are guaranteed that level is '> 0'
because the value of level _before_ reading 'next' is larger than 1
(otherwise we wouldn't have executed that code at all) this in turn
guarantees that 'level' after btrfs_read_buffer is 'level - 1' since
we verify this invariant in:

    btrfs_read_buffer
     btree_read_extent_buffer_pages
      btrfs_verify_level_key

This guarantees that level can never be '<= 0' so the warn on is
never triggered.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:51 +01:00
Nikolay Borisov
5c4b691eb8 btrfs: Remove WARN_ON in walk_log_tree
The log_root passed to walk_log_tree is guaranteed to have its
root_key.objectid always be BTRFS_TREE_LOG_OBJECTID. This is by
merit that all log roots of an ordinary root are allocated in
alloc_log_tree which hard-codes objectid to be BTRFS_TREE_LOG_OBJECTID.

In case walk_log_tree is called for a log tree found by btrfs_read_fs_root
in btrfs_recover_log_trees, that function already ensures
found_key.objectid is BTRFS_TREE_LOG_OBJECTID.

No functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:51 +01:00
Nikolay Borisov
a0fbf736d3 btrfs: Rename __btrfs_free_reserved_extent to btrfs_pin_reserved_extent
__btrfs_free_reserved_extent now performs the actions of
btrfs_free_and_pin_reserved_extent. But this name is a bit of a
misnomer, since the extent is not really freed but just pinned. Reflect
this in the new name. No semantics changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:51 +01:00
Nikolay Borisov
7ef54d54bf btrfs: Open code __btrfs_free_reserved_extent in btrfs_free_reserved_extent
__btrfs_free_reserved_extent performs 2 entirely different operations
depending on whether its 'pin' argument is true or false. This patch
lifts the 2nd case (pin is false) into it's sole caller
btrfs_free_reserved_extent. No semantics changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:51 +01:00
Nikolay Borisov
4eaaec24c0 btrfs: Don't discard unwritten extents
All callers of btrfs_free_reserved_extent (respectively
__btrfs_free_reserved_extent with in set to 0) pass in extents which
have only been reserved but not yet written to. Namely,

* in cow_file_range that function is called only if create_io_em fails
  or btrfs_add_ordered_extent fail, both of which happen _before_ any IO
  is submitted to the newly reserved range

* in submit_compressed_extents the code flow is similar -
  out_free_reserve can be called only before
  btrfs_submit_compressed_write which is where any writes to the range
  could occur

* btrfs_new_extent_direct also calls btrfs_free_reserved_extent only
  if extent_map fails, before any IO is issued

* __btrfs_prealloc_file_range also calls btrfs_free_reserved_extent
  in case insertion of the metadata fails

* btrfs_alloc_tree_block again can only be called in case in-memory
  operations fail, before any IO is submitted

* btrfs_finish_ordered_io - this is the only caller where discarding
  the extent could have a material effect, since it can be called for
  an extent which was partially written.

With this change the submission of discards is optimised since discards
are now not being created for extents which are known to not have been
touched on disk.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:50 +01:00
Marcos Paulo de Souza
8a36e408d4 btrfs: qgroup: return ENOTCONN instead of EINVAL when quotas are not enabled
[PROBLEM]
qgroup create/remove code is currently returning EINVAL when the user
tries to create a qgroup on a subvolume without quota enabled. EINVAL is
already being used for too many error scenarios so that is hard to
depict what is the problem.

[FIX]
Currently scrub and balance code return -ENOTCONN when the user tries to
cancel/pause and no scrub or balance is currently running for the
desired subvolume. Do the same here by returning -ENOTCONN  when a user
tries to create/delete/assing/list a qgroup on a subvolume without quota
enabled.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:50 +01:00
Marcos Paulo de Souza
e3b0edd297 btrfs: qgroup: remove one-time use variables for quota_root checks
Remove some variables that are set only to be checked later, and never
used.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:50 +01:00
Anand Jain
bc036bb335 btrfs: sysfs, merge btrfs_sysfs_add devices_kobj and fsid
Merge btrfs_sysfs_add_fsid() and btrfs_sysfs_add_devices_kobj() functions
as these two are small and they are called one after the other.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:50 +01:00
Anand Jain
be2cf92e0a btrfs: sysfs, rename btrfs_sysfs_add_device()
btrfs_sysfs_add_device() creates the directory
/sys/fs/btrfs/UUID/devices but its function name is misleading. Rename
it to btrfs_sysfs_add_devices_kobj() instead. No functional changes.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:50 +01:00
Anand Jain
c6761a9ed3 btrfs: sysfs, btrfs_sysfs_add_fsid() drop unused argument parent
Commit 24bd69cb ("Btrfs: sysfs: add support to add parent for fsid")
added parent argument in preparation to show the seed fsid under the
sprout fsid as in the patch [1] in the mailing list.

 [1] Btrfs: sysfs: support seed devices in the sysfs layout

But later this idea was superseded by another idea to rename the fsid as
in the commit f93c39970b ("btrfs: factor out sysfs code for updating
sprout fsid").

So we don't need parent argument anymore.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:49 +01:00
Anand Jain
b5501504cb btrfs: sysfs, rename devices kobject holder to devices_kobj
The struct member btrfs_device::device_dir_kobj holds the kobj of the
sysfs directory /sys/fs/btrfs/UUID/devices, so rename it from
device_dir_kobj to devices_kobj. No functional changes.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:49 +01:00
David Sterba
db26a02449 btrfs: fill ncopies for all raid table entries
Make the number of copies explicit even for entries that use the default
0 value for consistency.

Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:49 +01:00
David Sterba
e4f6c6be81 btrfs: use raid_attr table in calc_stripe_length for nparity
The table is already used for ncopies, replace open coding of stripes
with the raid_attr value.

Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:49 +01:00
Filipe Manana
0e56315ca1 Btrfs: fix missing hole after hole punching and fsync when using NO_HOLES
When using the NO_HOLES feature, if we punch a hole into a file and then
fsync it, there are cases where a subsequent fsync will miss the fact that
a hole was punched, resulting in the holes not existing after replaying
the log tree.

Essentially these cases all imply that, tree-log.c:copy_items(), is not
invoked for the leafs that delimit holes, because nothing changed those
leafs in the current transaction. And it's precisely copy_items() where
we currenly detect and log holes, which works as long as the holes are
between file extent items in the input leaf or between the beginning of
input leaf and the previous leaf or between the last item in the leaf
and the next leaf.

First example where we miss a hole:

  *) The extent items of the inode span multiple leafs;

  *) The punched hole covers a range that affects only the extent items of
     the first leaf;

  *) The fsync operation is done in full mode (BTRFS_INODE_NEEDS_FULL_SYNC
     is set in the inode's runtime flags).

  That results in the hole not existing after replaying the log tree.

  For example, if the fs/subvolume tree has the following layout for a
  particular inode:

      Leaf N, generation 10:

      [ ... INODE_ITEM INODE_REF EXTENT_ITEM (0 64K) EXTENT_ITEM (64K 128K) ]

      Leaf N + 1, generation 10:

      [ EXTENT_ITEM (128K 64K) ... ]

  If at transaction 11 we punch a hole coverting the range [0, 128K[, we end
  up dropping the two extent items from leaf N, but we don't touch the other
  leaf, so we end up in the following state:

      Leaf N, generation 11:

      [ ... INODE_ITEM INODE_REF ]

      Leaf N + 1, generation 10:

      [ EXTENT_ITEM (128K 64K) ... ]

  A full fsync after punching the hole will only process leaf N because it
  was modified in the current transaction, but not leaf N + 1, since it
  was not modified in the current transaction (generation 10 and not 11).
  As a result the fsync will not log any holes, because it didn't process
  any leaf with extent items.

Second example where we will miss a hole:

  *) An inode as its items spanning 5 (or more) leafs;

  *) A hole is punched and it covers only the extents items of the 3rd
     leaf. This resulsts in deleting the entire leaf and not touching any
     of the other leafs.

  So the only leaf that is modified in the current transaction, when
  punching the hole, is the first leaf, which contains the inode item.
  During the full fsync, the only leaf that is passed to copy_items()
  is that first leaf, and that's not enough for the hole detection
  code in copy_items() to determine there's a hole between the last
  file extent item in the 2nd leaf and the first file extent item in
  the 3rd leaf (which was the 4th leaf before punching the hole).

Fix this by scanning all leafs and punch holes as necessary when doing a
full fsync (less common than a non-full fsync) when the NO_HOLES feature
is enabled. The lack of explicit file extent items to mark holes makes it
necessary to scan existing extents to determine if holes exist.

A test case for fstests follows soon.

Fixes: 16e7549f04 ("Btrfs: incompatible format change to remove hole extents")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-20 16:40:49 +01:00
Linus Torvalds
effaf90137 for-5.5-rc6-tag
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Merge tag 'for-5.5-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "A few more fixes that have been in the works during last twp weeks.
  All have a user visible effect and are stable material:

   - scrub: properly update progress after calling cancel ioctl, calling
     'resume' would start from the beginning otherwise

   - fix subvolume reference removal, after moving out of the original
     path the reference is not recognized and will lead to transaction
     abort

   - fix reloc root lifetime checks, could lead to crashes when there's
     subvolume cleaning running in parallel

   - fix memory leak when quotas get disabled in the middle of extent
     accounting

   - fix transaction abort in case of balance being started on degraded
     mount on eg. RAID1"

* tag 'for-5.5-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: check rw_devices, not num_devices for balance
  Btrfs: always copy scrub arguments back to user space
  btrfs: relocation: fix reloc_root lifespan and access
  btrfs: fix memory leak in qgroup accounting
  btrfs: do not delete mismatched root refs
  btrfs: fix invalid removal of root ref
  btrfs: rework arguments of btrfs_unlink_subvol
2020-01-17 11:21:05 -08:00
Josef Bacik
b35cf1f0bf btrfs: check rw_devices, not num_devices for balance
The fstest btrfs/154 reports

  [ 8675.381709] BTRFS: Transaction aborted (error -28)
  [ 8675.383302] WARNING: CPU: 1 PID: 31900 at fs/btrfs/block-group.c:2038 btrfs_create_pending_block_groups+0x1e0/0x1f0 [btrfs]
  [ 8675.390925] CPU: 1 PID: 31900 Comm: btrfs Not tainted 5.5.0-rc6-default+ #935
  [ 8675.392780] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014
  [ 8675.395452] RIP: 0010:btrfs_create_pending_block_groups+0x1e0/0x1f0 [btrfs]
  [ 8675.402672] RSP: 0018:ffffb2090888fb00 EFLAGS: 00010286
  [ 8675.404413] RAX: 0000000000000000 RBX: ffff92026dfa91c8 RCX: 0000000000000001
  [ 8675.406609] RDX: 0000000000000000 RSI: ffffffff8e100899 RDI: ffffffff8e100971
  [ 8675.408775] RBP: ffff920247c61660 R08: 0000000000000000 R09: 0000000000000000
  [ 8675.410978] R10: 0000000000000000 R11: 0000000000000000 R12: 00000000ffffffe4
  [ 8675.412647] R13: ffff92026db74000 R14: ffff920247c616b8 R15: ffff92026dfbc000
  [ 8675.413994] FS:  00007fd5e57248c0(0000) GS:ffff92027d800000(0000) knlGS:0000000000000000
  [ 8675.416146] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [ 8675.417833] CR2: 0000564aa51682d8 CR3: 000000006dcbc004 CR4: 0000000000160ee0
  [ 8675.419801] Call Trace:
  [ 8675.420742]  btrfs_start_dirty_block_groups+0x355/0x480 [btrfs]
  [ 8675.422600]  btrfs_commit_transaction+0xc8/0xaf0 [btrfs]
  [ 8675.424335]  reset_balance_state+0x14a/0x190 [btrfs]
  [ 8675.425824]  btrfs_balance.cold+0xe7/0x154 [btrfs]
  [ 8675.427313]  ? kmem_cache_alloc_trace+0x235/0x2c0
  [ 8675.428663]  btrfs_ioctl_balance+0x298/0x350 [btrfs]
  [ 8675.430285]  btrfs_ioctl+0x466/0x2550 [btrfs]
  [ 8675.431788]  ? mem_cgroup_charge_statistics+0x51/0xf0
  [ 8675.433487]  ? mem_cgroup_commit_charge+0x56/0x400
  [ 8675.435122]  ? do_raw_spin_unlock+0x4b/0xc0
  [ 8675.436618]  ? _raw_spin_unlock+0x1f/0x30
  [ 8675.438093]  ? __handle_mm_fault+0x499/0x740
  [ 8675.439619]  ? do_vfs_ioctl+0x56e/0x770
  [ 8675.441034]  do_vfs_ioctl+0x56e/0x770
  [ 8675.442411]  ksys_ioctl+0x3a/0x70
  [ 8675.443718]  ? trace_hardirqs_off_thunk+0x1a/0x1c
  [ 8675.445333]  __x64_sys_ioctl+0x16/0x20
  [ 8675.446705]  do_syscall_64+0x50/0x210
  [ 8675.448059]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [ 8675.479187] BTRFS: error (device vdb) in btrfs_create_pending_block_groups:2038: errno=-28 No space left

We now use btrfs_can_overcommit() to see if we can flip a block group
read only.  Before this would fail because we weren't taking into
account the usable un-allocated space for allocating chunks.  With my
patches we were allowed to do the balance, which is technically correct.

The test is trying to start balance on degraded mount.  So now we're
trying to allocate a chunk and cannot because we want to allocate a
RAID1 chunk, but there's only 1 device that's available for usage.  This
results in an ENOSPC.

But we shouldn't even be making it this far, we don't have enough
devices to restripe.  The problem is we're using btrfs_num_devices(),
that also includes missing devices. That's not actually what we want, we
need to use rw_devices.

The chunk_mutex is not needed here, rw_devices changes only in device
add, remove or replace, all are excluded by EXCL_OP mechanism.

Fixes: e4d8ec0f65 ("Btrfs: implement online profile changing")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add stacktrace, update changelog, drop chunk_mutex ]
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-17 15:40:54 +01:00
Filipe Manana
5afe6ce748 Btrfs: always copy scrub arguments back to user space
If scrub returns an error we are not copying back the scrub arguments
structure to user space. This prevents user space to know how much
progress scrub has done if an error happened - this includes -ECANCELED
which is returned when users ask for scrub to stop. A particular use
case, which is used in btrfs-progs, is to resume scrub after it is
canceled, in that case it relies on checking the progress from the scrub
arguments structure and then use that progress in a call to resume
scrub.

So fix this by always copying the scrub arguments structure to user
space, overwriting the value returned to user space with -EFAULT only if
copying the structure failed to let user space know that either that
copying did not happen, and therefore the structure is stale, or it
happened partially and the structure is probably not valid and corrupt
due to the partial copy.

Reported-by: Graham Cobb <g.btrfs@cobb.uk.net>
Link: https://lore.kernel.org/linux-btrfs/d0a97688-78be-08de-ca7d-bcb4c7fb397e@cobb.uk.net/
Fixes: 06fe39ab15 ("Btrfs: do not overwrite scrub error with fault error in scrub ioctl")
CC: stable@vger.kernel.org # 5.1+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Tested-by: Graham Cobb <g.btrfs@cobb.uk.net>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-17 15:28:52 +01:00
Qu Wenruo
6282675e67 btrfs: relocation: fix reloc_root lifespan and access
[BUG]
There are several different KASAN reports for balance + snapshot
workloads.  Involved call paths include:

   should_ignore_root+0x54/0xb0 [btrfs]
   build_backref_tree+0x11af/0x2280 [btrfs]
   relocate_tree_blocks+0x391/0xb80 [btrfs]
   relocate_block_group+0x3e5/0xa00 [btrfs]
   btrfs_relocate_block_group+0x240/0x4d0 [btrfs]
   btrfs_relocate_chunk+0x53/0xf0 [btrfs]
   btrfs_balance+0xc91/0x1840 [btrfs]
   btrfs_ioctl_balance+0x416/0x4e0 [btrfs]
   btrfs_ioctl+0x8af/0x3e60 [btrfs]
   do_vfs_ioctl+0x831/0xb10

   create_reloc_root+0x9f/0x460 [btrfs]
   btrfs_reloc_post_snapshot+0xff/0x6c0 [btrfs]
   create_pending_snapshot+0xa9b/0x15f0 [btrfs]
   create_pending_snapshots+0x111/0x140 [btrfs]
   btrfs_commit_transaction+0x7a6/0x1360 [btrfs]
   btrfs_mksubvol+0x915/0x960 [btrfs]
   btrfs_ioctl_snap_create_transid+0x1d5/0x1e0 [btrfs]
   btrfs_ioctl_snap_create_v2+0x1d3/0x270 [btrfs]
   btrfs_ioctl+0x241b/0x3e60 [btrfs]
   do_vfs_ioctl+0x831/0xb10

   btrfs_reloc_pre_snapshot+0x85/0xc0 [btrfs]
   create_pending_snapshot+0x209/0x15f0 [btrfs]
   create_pending_snapshots+0x111/0x140 [btrfs]
   btrfs_commit_transaction+0x7a6/0x1360 [btrfs]
   btrfs_mksubvol+0x915/0x960 [btrfs]
   btrfs_ioctl_snap_create_transid+0x1d5/0x1e0 [btrfs]
   btrfs_ioctl_snap_create_v2+0x1d3/0x270 [btrfs]
   btrfs_ioctl+0x241b/0x3e60 [btrfs]
   do_vfs_ioctl+0x831/0xb10

[CAUSE]
All these call sites are only relying on root->reloc_root, which can
undergo btrfs_drop_snapshot(), and since we don't have real refcount
based protection to reloc roots, we can reach already dropped reloc
root, triggering KASAN.

[FIX]
To avoid such access to unstable root->reloc_root, we should check
BTRFS_ROOT_DEAD_RELOC_TREE bit first.

This patch introduces wrappers that provide the correct way to check the
bit with memory barriers protection.

Most callers don't distinguish merged reloc tree and no reloc tree.  The
only exception is should_ignore_root(), as merged reloc tree can be
ignored, while no reloc tree shouldn't.

[CRITICAL SECTION ANALYSIS]
Although test_bit()/set_bit()/clear_bit() doesn't imply a barrier, the
DEAD_RELOC_TREE bit has extra help from transaction as a higher level
barrier, the lifespan of root::reloc_root and DEAD_RELOC_TREE bit are:

	NULL: reloc_root is NULL	PTR: reloc_root is not NULL
	0: DEAD_RELOC_ROOT bit not set	DEAD: DEAD_RELOC_ROOT bit set

	(NULL, 0)    Initial state		 __
	  |					 /\ Section A
        btrfs_init_reloc_root()			 \/
	  |				 	 __
	(PTR, 0)     reloc_root initialized      /\
          |					 |
	btrfs_update_reloc_root()		 |  Section B
          |					 |
	(PTR, DEAD)  reloc_root has been merged  \/
          |					 __
	=== btrfs_commit_transaction() ====================
	  |					 /\
	clean_dirty_subvols()			 |
	  |					 |  Section C
	(NULL, DEAD) reloc_root cleanup starts   \/
          |					 __
	btrfs_drop_snapshot()			 /\
	  |					 |  Section D
	(NULL, 0)    Back to initial state	 \/

Every have_reloc_root() or test_bit(DEAD_RELOC_ROOT) caller holds
transaction handle, so none of such caller can cross transaction boundary.

In Section A, every caller just found no DEAD bit, and grab reloc_root.

In the cross section A-B, caller may get no DEAD bit, but since reloc_root
is still completely valid thus accessing reloc_root is completely safe.

No test_bit() caller can cross the boundary of Section B and Section C.

In Section C, every caller found the DEAD bit, so no one will access
reloc_root.

In the cross section C-D, either caller gets the DEAD bit set, avoiding
access reloc_root no matter if it's safe or not.  Or caller get the DEAD
bit cleared, then access reloc_root, which is already NULL, nothing will
be wrong.

The memory write barriers are between the reloc_root updates and bit
set/clear, the pairing read side is before test_bit.

Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Fixes: d2311e6985 ("btrfs: relocation: Delay reloc tree deletion after merge_reloc_roots")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ barriers ]
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-13 23:10:56 +01:00
Johannes Thumshirn
26ef8493e1 btrfs: fix memory leak in qgroup accounting
When running xfstests on the current btrfs I get the following splat from
kmemleak:

unreferenced object 0xffff88821b2404e0 (size 32):
  comm "kworker/u4:7", pid 26663, jiffies 4295283698 (age 8.776s)
  hex dump (first 32 bytes):
    01 00 00 00 00 00 00 00 10 ff fd 26 82 88 ff ff  ...........&....
    10 ff fd 26 82 88 ff ff 20 ff fd 26 82 88 ff ff  ...&.... ..&....
  backtrace:
    [<00000000f94fd43f>] ulist_alloc+0x25/0x60 [btrfs]
    [<00000000fd023d99>] btrfs_find_all_roots_safe+0x41/0x100 [btrfs]
    [<000000008f17bd32>] btrfs_find_all_roots+0x52/0x70 [btrfs]
    [<00000000b7660afb>] btrfs_qgroup_rescan_worker+0x343/0x680 [btrfs]
    [<0000000058e66778>] btrfs_work_helper+0xac/0x1e0 [btrfs]
    [<00000000f0188930>] process_one_work+0x1cf/0x350
    [<00000000af5f2f8e>] worker_thread+0x28/0x3c0
    [<00000000b55a1add>] kthread+0x109/0x120
    [<00000000f88cbd17>] ret_from_fork+0x35/0x40

This corresponds to:

  (gdb) l *(btrfs_find_all_roots_safe+0x41)
  0x8d7e1 is in btrfs_find_all_roots_safe (fs/btrfs/backref.c:1413).
  1408
  1409            tmp = ulist_alloc(GFP_NOFS);
  1410            if (!tmp)
  1411                    return -ENOMEM;
  1412            *roots = ulist_alloc(GFP_NOFS);
  1413            if (!*roots) {
  1414                    ulist_free(tmp);
  1415                    return -ENOMEM;
  1416            }
  1417

Following the lifetime of the allocated 'roots' ulist, it gets freed
again in btrfs_qgroup_account_extent().

But this does not happen if the function is called with the
'BTRFS_FS_QUOTA_ENABLED' flag cleared, then btrfs_qgroup_account_extent()
does a short leave and directly returns.

Instead of directly returning we should jump to the 'out_free' in order to
free all resources as expected.

CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
[ add comment ]
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-08 17:56:17 +01:00
Josef Bacik
423a716cd7 btrfs: do not delete mismatched root refs
btrfs_del_root_ref() will simply WARN_ON() if the ref doesn't match in
any way, and then continue to delete the reference.  This shouldn't
happen, we have these values because there's more to the reference than
the original root and the sub root.  If any of these checks fail, return
-ENOENT.

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-08 14:44:24 +01:00
Josef Bacik
d49d3287e7 btrfs: fix invalid removal of root ref
If we have the following sequence of events

  btrfs sub create A
  btrfs sub create A/B
  btrfs sub snap A C
  mkdir C/foo
  mv A/B C/foo
  rm -rf *

We will end up with a transaction abort.

The reason for this is because we create a root ref for B pointing to A.
When we create a snapshot of C we still have B in our tree, but because
the root ref points to A and not C we will make it appear to be empty.

The problem happens when we move B into C.  This removes the root ref
for B pointing to A and adds a ref of B pointing to C.  When we rmdir C
we'll see that we have a ref to our root and remove the root ref,
despite not actually matching our reference name.

Now btrfs_del_root_ref() allowing this to work is a bug as well, however
we know that this inode does not actually point to a root ref in the
first place, so we shouldn't be calling btrfs_del_root_ref() in the
first place and instead simply look up our dir index for this item and
do the rest of the removal.

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-08 14:44:23 +01:00
Josef Bacik
045d3967b6 btrfs: rework arguments of btrfs_unlink_subvol
btrfs_unlink_subvol takes the name of the dentry and the root objectid
based on what kind of inode this is, either a real subvolume link or a
empty one that we inherited as a snapshot.  We need to fix how we unlink
in the case for BTRFS_EMPTY_SUBVOL_DIR_OBJECTID in the future, so rework
btrfs_unlink_subvol to just take the dentry and handle getting the right
objectid given the type of inode this is.  There is no functional change
here, simply pushing the work into btrfs_unlink_subvol() proper.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-08 14:43:34 +01:00
Linus Torvalds
3a562aee72 for-5.5-rc4-tag
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Merge tag 'for-5.5-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "A few fixes for btrfs:

   - blkcg accounting problem with compression that could stall writes

   - setting up blkcg bio for compression crashes due to NULL bdev
     pointer

   - fix possible infinite loop in writeback for nocow files (here
     possible means almost impossible, 13 things that need to happen to
     trigger it)"

* tag 'for-5.5-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Btrfs: fix infinite loop during nocow writeback due to race
  btrfs: fix compressed write bio blkcg attribution
  btrfs: punt all bios created in btrfs_submit_compressed_write()
2020-01-03 12:20:21 -08:00
Filipe Manana
de7999afed Btrfs: fix infinite loop during nocow writeback due to race
When starting writeback for a range that covers part of a preallocated
extent, due to a race with writeback for another range that also covers
another part of the same preallocated extent, we can end up in an infinite
loop.

Consider the following example where for inode 280 we have two dirty
ranges:

  range A, from 294912 to 303103, 8192 bytes
  range B, from 348160 to 438271, 90112 bytes

and we have the following file extent item layout for our inode:

  leaf 38895616 gen 24544 total ptrs 29 free space 13820 owner 5
      (...)
      item 27 key (280 108 200704) itemoff 14598 itemsize 53
          extent data disk bytenr 0 nr 0 type 1 (regular)
          extent data offset 0 nr 94208 ram 94208
      item 28 key (280 108 294912) itemoff 14545 itemsize 53
          extent data disk bytenr 10433052672 nr 81920 type 2 (prealloc)
          extent data offset 0 nr 81920 ram 81920

Then the following happens:

1) Writeback starts for range B (from 348160 to 438271), execution of
   run_delalloc_nocow() starts;

2) The first iteration of run_delalloc_nocow()'s whil loop leaves us at
   the extent item at slot 28, pointing to the prealloc extent item
   covering the range from 294912 to 376831. This extent covers part of
   our range;

3) An ordered extent is created against that extent, covering the file
   range from 348160 to 376831 (28672 bytes);

4) We adjust 'cur_offset' to 376832 and move on to the next iteration of
   the while loop;

5) The call to btrfs_lookup_file_extent() leaves us at the same leaf,
   pointing to slot 29, 1 slot after the last item (the extent item
   we processed in the previous iteration);

6) Because we are a slot beyond the last item, we call btrfs_next_leaf(),
   which releases the search path before doing a another search for the
   last key of the leaf (280 108 294912);

7) Right after btrfs_next_leaf() released the path, and before it did
   another search for the last key of the leaf, writeback for the range
   A (from 294912 to 303103) completes (it was previously started at
   some point);

8) Upon completion of the ordered extent for range A, the prealloc extent
   we previously found got split into two extent items, one covering the
   range from 294912 to 303103 (8192 bytes), with a type of regular extent
   (and no longer prealloc) and another covering the range from 303104 to
   376831 (73728 bytes), with a type of prealloc and an offset of 8192
   bytes. So our leaf now has the following layout:

     leaf 38895616 gen 24544 total ptrs 31 free space 13664 owner 5
         (...)
         item 27 key (280 108 200704) itemoff 14598 itemsize 53
             extent data disk bytenr 0 nr 0 type 1
             extent data offset 0 nr 8192 ram 94208
         item 28 key (280 108 208896) itemoff 14545 itemsize 53
             extent data disk bytenr 10433142784 nr 86016 type 1
             extent data offset 0 nr 86016 ram 86016
         item 29 key (280 108 294912) itemoff 14492 itemsize 53
             extent data disk bytenr 10433052672 nr 81920 type 1
             extent data offset 0 nr 8192 ram 81920
         item 30 key (280 108 303104) itemoff 14439 itemsize 53
             extent data disk bytenr 10433052672 nr 81920 type 2
             extent data offset 8192 nr 73728 ram 81920

9) After btrfs_next_leaf() returns, we have our path pointing to that same
   leaf and at slot 30, since it has a key we didn't have before and it's
   the first key greater then the key that was previously the last key of
   the leaf (key (280 108 294912));

10) The extent item at slot 30 covers the range from 303104 to 376831
    which is in our target range, so we process it, despite having already
    created an ordered extent against this extent for the file range from
    348160 to 376831. This is because we skip to the next extent item only
    if its end is less than or equals to the start of our delalloc range,
    and not less than or equals to the current offset ('cur_offset');

11) As a result we compute 'num_bytes' as:

    num_bytes = min(end + 1, extent_end) - cur_offset;
              = min(438271 + 1, 376832) - 376832 = 0

12) We then call create_io_em() for a 0 bytes range starting at offset
    376832;

13) Then create_io_em() enters an infinite loop because its calls to
    btrfs_drop_extent_cache() do nothing due to the 0 length range
    passed to it. So no existing extent maps that cover the offset
    376832 get removed, and therefore calls to add_extent_mapping()
    return -EEXIST, resulting in an infinite loop. This loop from
    create_io_em() is the following:

    do {
        btrfs_drop_extent_cache(BTRFS_I(inode), em->start,
                                em->start + em->len - 1, 0);
        write_lock(&em_tree->lock);
        ret = add_extent_mapping(em_tree, em, 1);
        write_unlock(&em_tree->lock);
        /*
         * The caller has taken lock_extent(), who could race with us
         * to add em?
         */
    } while (ret == -EEXIST);

Also, each call to btrfs_drop_extent_cache() triggers a warning because
the start offset passed to it (376832) is smaller then the end offset
(376832 - 1) passed to it by -1, due to the 0 length:

  [258532.052621] ------------[ cut here ]------------
  [258532.052643] WARNING: CPU: 0 PID: 9987 at fs/btrfs/file.c:602 btrfs_drop_extent_cache+0x3f4/0x590 [btrfs]
  (...)
  [258532.052672] CPU: 0 PID: 9987 Comm: fsx Tainted: G        W         5.4.0-rc7-btrfs-next-64 #1
  [258532.052673] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014
  [258532.052691] RIP: 0010:btrfs_drop_extent_cache+0x3f4/0x590 [btrfs]
  (...)
  [258532.052695] RSP: 0018:ffffb4be0153f860 EFLAGS: 00010287
  [258532.052700] RAX: ffff975b445ee360 RBX: ffff975b44eb3e08 RCX: 0000000000000000
  [258532.052700] RDX: 0000000000038fff RSI: 0000000000039000 RDI: ffff975b445ee308
  [258532.052700] RBP: 0000000000038fff R08: 0000000000000000 R09: 0000000000000001
  [258532.052701] R10: ffff975b513c5c10 R11: 00000000e3c0cfa9 R12: 0000000000039000
  [258532.052703] R13: ffff975b445ee360 R14: 00000000ffffffef R15: ffff975b445ee308
  [258532.052705] FS:  00007f86a821de80(0000) GS:ffff975b76a00000(0000) knlGS:0000000000000000
  [258532.052707] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [258532.052708] CR2: 00007fdacf0f3ab4 CR3: 00000001f9d26002 CR4: 00000000003606f0
  [258532.052712] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  [258532.052717] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  [258532.052717] Call Trace:
  [258532.052718]  ? preempt_schedule_common+0x32/0x70
  [258532.052722]  ? ___preempt_schedule+0x16/0x20
  [258532.052741]  create_io_em+0xff/0x180 [btrfs]
  [258532.052767]  run_delalloc_nocow+0x942/0xb10 [btrfs]
  [258532.052791]  btrfs_run_delalloc_range+0x30b/0x520 [btrfs]
  [258532.052812]  ? find_lock_delalloc_range+0x221/0x250 [btrfs]
  [258532.052834]  writepage_delalloc+0xe4/0x140 [btrfs]
  [258532.052855]  __extent_writepage+0x110/0x4e0 [btrfs]
  [258532.052876]  extent_write_cache_pages+0x21c/0x480 [btrfs]
  [258532.052906]  extent_writepages+0x52/0xb0 [btrfs]
  [258532.052911]  do_writepages+0x23/0x80
  [258532.052915]  __filemap_fdatawrite_range+0xd2/0x110
  [258532.052938]  btrfs_fdatawrite_range+0x1b/0x50 [btrfs]
  [258532.052954]  start_ordered_ops+0x57/0xa0 [btrfs]
  [258532.052973]  ? btrfs_sync_file+0x225/0x490 [btrfs]
  [258532.052988]  btrfs_sync_file+0x225/0x490 [btrfs]
  [258532.052997]  __x64_sys_msync+0x199/0x200
  [258532.053004]  do_syscall_64+0x5c/0x250
  [258532.053007]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [258532.053010] RIP: 0033:0x7f86a7dfd760
  (...)
  [258532.053014] RSP: 002b:00007ffd99af0368 EFLAGS: 00000246 ORIG_RAX: 000000000000001a
  [258532.053016] RAX: ffffffffffffffda RBX: 0000000000000ec9 RCX: 00007f86a7dfd760
  [258532.053017] RDX: 0000000000000004 RSI: 000000000000836c RDI: 00007f86a8221000
  [258532.053019] RBP: 0000000000021ec9 R08: 0000000000000003 R09: 00007f86a812037c
  [258532.053020] R10: 0000000000000001 R11: 0000000000000246 R12: 00000000000074a3
  [258532.053021] R13: 00007f86a8221000 R14: 000000000000836c R15: 0000000000000001
  [258532.053032] irq event stamp: 1653450494
  [258532.053035] hardirqs last  enabled at (1653450493): [<ffffffff9dec69f9>] _raw_spin_unlock_irq+0x29/0x50
  [258532.053037] hardirqs last disabled at (1653450494): [<ffffffff9d4048ea>] trace_hardirqs_off_thunk+0x1a/0x20
  [258532.053039] softirqs last  enabled at (1653449852): [<ffffffff9e200466>] __do_softirq+0x466/0x6bd
  [258532.053042] softirqs last disabled at (1653449845): [<ffffffff9d4c8a0c>] irq_exit+0xec/0x120
  [258532.053043] ---[ end trace 8476fce13d9ce20a ]---

Which results in flooding dmesg/syslog since btrfs_drop_extent_cache()
uses WARN_ON() and not WARN_ON_ONCE().

So fix this issue by changing run_delalloc_nocow()'s loop to move to the
next extent item when the current extent item ends at at offset less than
or equals to the current offset instead of the start offset.

Fixes: 80ff385665 ("Btrfs: update nodatacow code v2")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-12-30 16:13:20 +01:00
Dennis Zhou
46bcff2bfc btrfs: fix compressed write bio blkcg attribution
Bio attribution is handled at bio_set_dev() as once we have a device, we
have a corresponding request_queue and then can derive the current css.
In special cases, we want to attribute to bio to someone else. This can
be done by calling bio_associate_blkg_from_css() or
kthread_associate_blkcg() depending on the scenario. Btrfs does this for
compressed writeback as they are handled by kworkers, so the latter can
be done here.

Commit 1a41802701 ("btrfs: drop bio_set_dev where not needed") removes
early bio_set_dev() calls prior to submit_stripe_bio(). This breaks the
above assumption that we'll have a request_queue when we are doing
association. To fix this, switch to using kthread_associate_blkcg().

Without this, we crash in btrfs/024:

  [ 3052.093088] BUG: kernel NULL pointer dereference, address: 0000000000000510
  [ 3052.107013] #PF: supervisor read access in kernel mode
  [ 3052.107014] #PF: error_code(0x0000) - not-present page
  [ 3052.107015] PGD 0 P4D 0
  [ 3052.107021] Oops: 0000 [#1] SMP
  [ 3052.138904] CPU: 42 PID: 201270 Comm: kworker/u161:0 Kdump: loaded Not tainted 5.5.0-rc1-00062-g4852d8ac90a9 #712
  [ 3052.138905] Hardware name: Quanta Tioga Pass Single Side 01-0032211004/Tioga Pass Single Side, BIOS F08_3A18 12/20/2018
  [ 3052.138912] Workqueue: btrfs-delalloc btrfs_work_helper
  [ 3052.191375] RIP: 0010:bio_associate_blkg_from_css+0x1e/0x3c0
  [ 3052.191379] RSP: 0018:ffffc900210cfc90 EFLAGS: 00010282
  [ 3052.191380] RAX: 0000000000000000 RBX: ffff88bfe5573c00 RCX: 0000000000000000
  [ 3052.191382] RDX: ffff889db48ec2f0 RSI: ffff88bfe5573c00 RDI: ffff889db48ec2f0
  [ 3052.191386] RBP: 0000000000000800 R08: 0000000000203bb0 R09: ffff889db16b2400
  [ 3052.293364] R10: 0000000000000000 R11: ffff88a07fffde80 R12: ffff889db48ec2f0
  [ 3052.293365] R13: 0000000000001000 R14: ffff889de82bc000 R15: ffff889e2b7bdcc8
  [ 3052.293367] FS:  0000000000000000(0000) GS:ffff889ffba00000(0000) knlGS:0000000000000000
  [ 3052.293368] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [ 3052.293369] CR2: 0000000000000510 CR3: 0000000002611001 CR4: 00000000007606e0
  [ 3052.293370] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  [ 3052.293371] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  [ 3052.293372] PKRU: 55555554
  [ 3052.293376] Call Trace:
  [ 3052.402552]  btrfs_submit_compressed_write+0x137/0x390
  [ 3052.402558]  submit_compressed_extents+0x40f/0x4c0
  [ 3052.422401]  btrfs_work_helper+0x246/0x5a0
  [ 3052.422408]  process_one_work+0x200/0x570
  [ 3052.438601]  ? process_one_work+0x180/0x570
  [ 3052.438605]  worker_thread+0x4c/0x3e0
  [ 3052.438614]  kthread+0x103/0x140
  [ 3052.460735]  ? process_one_work+0x570/0x570
  [ 3052.460737]  ? kthread_mod_delayed_work+0xc0/0xc0
  [ 3052.460744]  ret_from_fork+0x24/0x30

Fixes: 1a41802701 ("btrfs: drop bio_set_dev where not needed")
Reported-by: Chris Murphy <chris@colorremedies.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-12-30 16:07:19 +01:00
Dennis Zhou
7b62e66cbb btrfs: punt all bios created in btrfs_submit_compressed_write()
Compressed writes happen in the background via kworkers. However, this
causes bios to be attributed to root bypassing any cgroup limits from
the actual writer. We tag the first bio with REQ_CGROUP_PUNT, which will
punt the bio to an appropriate cgroup specific workqueue and attribute
the IO properly. However, if btrfs_submit_compressed_write() creates a
new bio, we don't tag it the same way. Add the appropriate tagging for
subsequent bios.

Fixes: ec39f7696c ("Btrfs: use REQ_CGROUP_PUNT for worker thread submitted bios")
Reviewed-by: Chris Mason <clm@fb.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-12-30 16:07:16 +01:00
Ingo Molnar
1e5f8a3085 Linux 5.5-rc3
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Merge tag 'v5.5-rc3' into sched/core, to pick up fixes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-12-25 10:41:37 +01:00
Linus Torvalds
2187f215eb for-5.5-rc2-tag
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Merge tag 'for-5.5-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "A mix of regression fixes and regular fixes for stable trees:

   - fix swapped error messages for qgroup enable/rescan

   - fixes for NO_HOLES feature with clone range

   - fix deadlock between iget/srcu lock/synchronize srcu while freeing
     an inode

   - fix double lock on subvolume cross-rename

   - tree log fixes
      * fix missing data checksums after replaying a log tree
      * also teach tree-checker about this problem
      * skip log replay on orphaned roots

   - fix maximum devices constraints for RAID1C -3 and -4

   - send: don't print warning on read-only mount regarding orphan
     cleanup

   - error handling fixes"

* tag 'for-5.5-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: send: remove WARN_ON for readonly mount
  btrfs: do not leak reloc root if we fail to read the fs root
  btrfs: skip log replay on orphaned roots
  btrfs: handle ENOENT in btrfs_uuid_tree_iterate
  btrfs: abort transaction after failed inode updates in create_subvol
  Btrfs: fix hole extent items with a zero size after range cloning
  Btrfs: fix removal logic of the tree mod log that leads to use-after-free issues
  Btrfs: make tree checker detect checksum items with overlapping ranges
  Btrfs: fix missing data checksums after replaying a log tree
  btrfs: return error pointer from alloc_test_extent_buffer
  btrfs: fix devs_max constraints for raid1c3 and raid1c4
  btrfs: tree-checker: Fix error format string for size_t
  btrfs: don't double lock the subvol_sem for rename exchange
  btrfs: handle error in btrfs_cache_block_group
  btrfs: do not call synchronize_srcu() in inode_tree_del
  Btrfs: fix cloning range with a hole when using the NO_HOLES feature
  btrfs: Fix error messages in qgroup_rescan_init
2019-12-17 13:27:02 -08:00
Anand Jain
fbd542971a btrfs: send: remove WARN_ON for readonly mount
We log warning if root::orphan_cleanup_state is not set to
ORPHAN_CLEANUP_DONE in btrfs_ioctl_send(). However if the filesystem is
mounted as readonly we skip the orphan item cleanup during the lookup
and root::orphan_cleanup_state remains at the init state 0 instead of
ORPHAN_CLEANUP_DONE (2). So during send in btrfs_ioctl_send() we hit the
warning as below.

  WARN_ON(send_root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE);

WARNING: CPU: 0 PID: 2616 at /Volumes/ws/btrfs-devel/fs/btrfs/send.c:7090 btrfs_ioctl_send+0xb2f/0x18c0 [btrfs]
::
RIP: 0010:btrfs_ioctl_send+0xb2f/0x18c0 [btrfs]
::
Call Trace:
::
_btrfs_ioctl_send+0x7b/0x110 [btrfs]
btrfs_ioctl+0x150a/0x2b00 [btrfs]
::
do_vfs_ioctl+0xa9/0x620
? __fget+0xac/0xe0
ksys_ioctl+0x60/0x90
__x64_sys_ioctl+0x16/0x20
do_syscall_64+0x49/0x130
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reproducer:
  mkfs.btrfs -fq /dev/sdb
  mount /dev/sdb /btrfs
  btrfs subvolume create /btrfs/sv1
  btrfs subvolume snapshot -r /btrfs/sv1 /btrfs/ss1
  umount /btrfs
  mount -o ro /dev/sdb /btrfs
  btrfs send /btrfs/ss1 -f /tmp/f

The warning exists because having orphan inodes could confuse send and
cause it to fail or produce incorrect streams.  The two cases that would
cause such send failures, which are already fixed are:

1) Inodes that were unlinked - these are orphanized and remain with a
   link count of 0. These caused send operations to fail because it
   expected to always find at least one path for an inode. However this
   is no longer a problem since send is now able to deal with such
   inodes since commit 46b2f4590a ("Btrfs: fix send failure when root
   has deleted files still open") and treats them as having been
   completely removed (the state after an orphan cleanup is performed).

2) Inodes that were in the process of being truncated. These resulted in
   send not knowing about the truncation and potentially issue write
   operations full of zeroes for the range from the new file size to the
   old file size. This is no longer a problem because we no longer
   create orphan items for truncation since commit f7e9e8fc79 ("Btrfs:
   stop creating orphan items for truncate").

As such before these commits, the WARN_ON here provided a clue in case
something went wrong. Instead of being a warning against the
root::orphan_cleanup_state value, it could have been more accurate by
checking if there were actually any orphan items, and then issue a
warning only if any exists, but that would be more expensive to check.
Since orphanized inodes no longer cause problems for send, just remove
the warning.

Reported-by: Christoph Anton Mitterer <calestyo@scientia.net>
Link: https://lore.kernel.org/linux-btrfs/21cb5e8d059f6e1496a903fa7bfc0a297e2f5370.camel@scientia.net/
CC: stable@vger.kernel.org # 4.19+
Suggested-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-12-13 14:10:46 +01:00
Josef Bacik
ca1aa2818a btrfs: do not leak reloc root if we fail to read the fs root
If we fail to read the fs root corresponding with a reloc root we'll
just break out and free the reloc roots.  But we remove our current
reloc_root from this list higher up, which means we'll leak this
reloc_root.  Fix this by adding ourselves back to the reloc_roots list
so we are properly cleaned up.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-12-13 14:10:45 +01:00
Josef Bacik
9bc574de59 btrfs: skip log replay on orphaned roots
My fsstress modifications coupled with generic/475 uncovered a failure
to mount and replay the log if we hit a orphaned root.  We do not want
to replay the log for an orphan root, but it's completely legitimate to
have an orphaned root with a log attached.  Fix this by simply skipping
replaying the log.  We still need to pin it's root node so that we do
not overwrite it while replaying other logs, as we re-read the log root
at every stage of the replay.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-12-13 14:10:45 +01:00
Josef Bacik
714cd3e8cb btrfs: handle ENOENT in btrfs_uuid_tree_iterate
If we get an -ENOENT back from btrfs_uuid_iter_rem when iterating the
uuid tree we'll just continue and do btrfs_next_item().  However we've
done a btrfs_release_path() at this point and no longer have a valid
path.  So increment the key and go back and do a normal search.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-12-13 14:10:45 +01:00
Josef Bacik
c7e54b5102 btrfs: abort transaction after failed inode updates in create_subvol
We can just abort the transaction here, and in fact do that for every
other failure in this function except these two cases.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-12-13 14:10:44 +01:00